Flaş (fotoğraf)

Fotoğraf makinesi flaşlarının çalışması için enerji depolayan araçlar kondansatörlerdir. İlk flaşlar 19. yüzyılda kullanılan barutla anlık ışık sağlayan bir düzenek idi. Ampülün ve taşınabilir pillerin yaygınlaşması, fotoğraf makinalarında ve flaş aparatında pratik gelişmeler sağladı. Ayrı bir aparat iken zamanla fotoğraf makinası ile kombine hale geldi.

Kullanım alanı

Flaş, fotoğraf çekimi için ışığın yetersiz olduğu mekanlarda ortamın aydınlatılması için kullanılır. Fotoğrafın çekilmesi için mekanın sürekli aydınlık olması gerekmemekte, tam çekim anında sağlanan yüksek aydınlık düzeyi çekim için yeterli olmaktadır. Bu sebeple flaşa bağlanmış olan kondansatör çekim anında devreye sokulur ve depolanmış yüksek enerji bir anda boşaltılır, böylece anlık olarak yüksek aydınlık elde edilmiş olur. Kondansatörde depolanan elektrik enerjisinin çoğu ışık enerjisine bir kısmı da ısı enerjisine dönüşür, ancak flaş patladıktan sonra elle temasla flaşın ne kadar ısındığına bakılıp, depolanan enerjinin ne kadar büyük olduğu anlaşılabilir. Flaşın anlık olarak biriktirilen tüm enerjiyi harcaması kondansatör sayesinde olmaktadır. Kondansatörün aniden boşalması flaş ışığının parlak olmasını sağlar. Bundan dolayı flaşlar uzun süreli yanıp, lamba olarak kullanılamazlar, çünkü sadece bir anlık parlamaları için bile ihtiyaçları olan enerji yeterince yüksektir, dolayısıyla lamba olarak kullanılmaları çok daha yüksek enerji gerektireceğinden imkânsızdır. Çok kısa süreli ancak çok güçlü ışık sağlaması fotoğraflanması zor veya imkânsız olan kareleri çekilebilir hale getirir. Bu yönüyle fotoğrafçının vazgeçilmez ekipmanıdır. Çeşitleri geniş bir yelpaze oluşturur. Temelde çalışma şekilleri çok benzer olmakla birlikte tetikleme şekilleri ve hızları değişiklik gösterir. Doğrudan makinadan, mevcut başka bir flaştan, kızılötesi tetikleme ile uzaktan, kablo ile makinadan ya da birbirine senkron yahut asenkron flaşlarla birlikte tetiklenebilir.

FOTOĞRAF MAKINASI FLAŞI ILE 220 VOLT FLAŞÖR DEVRESI

Eski hurda Fotoğraf makinelerinizin Flaş parçalarını değerlendirmeniz için basit bir devre aslında makinelerin diğer parçalarıda iş görür şimdilik flaşör devresi ile idare edelim devrede kullandığım triyak T1213MH flaş yakmak için gücü yüksek daha düşük güçde triyaklar kullanılabilir elimde başka olmadığından kullanıldı flaşör devresinde kullanılan flaş ve bobin ucuz çin malı bir fotoğraf makina hurdasından söküldü delikli pertinaks üzerine montaj yapıldı işcilik biraz kötü pertinaks uygun değildi deneme amaçlı merak üzerine kurulan bir devre


DİKKAT: Devre yüksek voltaj ile çalışmaktadır dikkatli olun kondansatör bağlantılarına dikkat edin + – kutupları ters bağlarsanız yüksek voltajda büyük patlamalar olabilir devreyi çalıştırmadan önce Sigortalı Elektrik Hattı,koruyucu gözlük kullanın.


Malzeme Listesi
T1213MH Triyak 1 adet
1N4007 1000 volt 1 amper diyot 2 adet
47KΩ Direnç 2 adet
2.2MΩ Direnç 2 adet
22nf 400 volt kondansatör (kutupsuz) 1 adet
1uf 400v kondansatör (kutupsuz) 1 adet
4.7uf 63 volt kondansatör (kutuplu) 1 adet
30 volt diyak 1 adet

Devre ek besleme gerektirmez 220v ..240 volt şebeke voltajı ile kullanılabilir Kullanılan pasif eleman değerleri kıritik değil iki adet 47k yerine tek 100kΩ kullanılabilir iki adet 2.2m yerine tek 4.7m kullanılabilir ben pc güç kaynağındaki kondansatörleri kullandım 22nf 230v yerine 100nf 400v şebeke filtresinden alındı 1uf ise sürücü devreden 1n4007 yerine 1n4005 1n4006 ya da 1n5408 kullanılabilir flaşın yanma süresini 2,2mΩ dirençler ve 4.7uf kondansatör değerini değiştirerek ayarlayabilirsiniz

iki adet seri direnç kullanılma sebebi yüksek voltajlarda daha sağlıklı olması aslında bu yöntemin teorik bir açıklaması var ama hatırlamıyorum tek direnç ile yüksek voltajı karşılamak yerine voltajı 2 direnç ile zayıflatarak kullanmak dirençlerin ömrü ve direnç üzerinden beslenen bölüm için iyidir denilebilir bir çok smps devresinde kontrol ünitesinin start dirençleri bu şekilde olur.

Flaşör Devre Şeması :

flaş tüpüne giden iki kablo kondansatörün iki ucuna bağlıdır ve üzerinde 300 V( flaş tüpüne göre değişebilir) civarında bir gerilim olmalıdır. Üçüncü kablo ise tetikleme trafosundan 2000 V civarında bir tetikleme voltajı verir.

Devre ek besleme gerektirmez 220v ..240 volt şebeke voltajı ile kullanılabilir Kullanılan pasif eleman değerleri kıritik değil iki adet 47k yerine tek 100kΩ kullanılabilir iki adet 2.2m yerine tek 4.7m kullanılabilir ben pc güç kaynağındaki kondansatörleri kullandım 22nf 230v yerine 100nf 400v şebeke filtresinden alındı 1uf ise sürücü devreden 1n4007 yerine 1n4005 1n4006 ya da 1n5408 kullanılabilir flaşın yanma süresini 2,2mΩ dirençler ve 4.7uf kondansatör değerini değiştirerek ayarlayabilirsiniz

Fotoğraf Makinesi Flaşı ile Elektrik Şoku Veren Eldiven

Ewet arkadaşlar bu yazımızda eski fotoğraf makinelerinizin Flaş parçalarını değerlendirerek yapabileceğiniz Elektrik Şoku Veren Eldiven projesi yapacağız.

Proje için gerekli malzemeler:

Fotoğraf Makinesi
Kimyasallara karşı dayanıklı eldiven.
Devre montaj kutusu. 3*2*1,5 cm
Alüminyum Folyo
2* on-off toggle switch.
Bir tane basmalı (shack) anahtar.
AA pil tutucu ve tutkal.
Havya,lehim,zil teli,keski,tornavida vb.


İlk olarak fotoğraf makinesini tornavida yardımıyla sökerek başlıyoruz. Kamerayı açın ve üzerindeki herhangi bir elektronik devreye dokunmamaya çok dikkat edin. Pili dikkatlice çıkarın. Metal bir tornavida yardımıyla resimde 1 numara olarak gösterilen yerde bulunan kondansatörün iki bacağını kısa devre ettirin. Böylece kondansatör üzerideki akım boşalmış olacaktır.

Fotoğraf makinesinin flaş devre kısmını şekilde görüldüğü gibi plastik kasadan ayırıyoruz. Çıkarma işleminde devreye zarar vermemeye özen gözterin. Devrelerin montajı makine markaları ve modellerinde farklı olduğu için lütfen dikkatli olun.


Kondansatörün - ve + bacaklarından şekilde görüldüğü gibi iki adet kablo ucu çıkartıyoruz. Çektiğimiz kablonun 220 volta dayanıklı omasına dikkat edin. Flaş patlaması anında ortaya çıkan yüksek voltajı burada bulunan kondansatörün bacaklarından çekeceğiz.

Elektrik bantı ile uçları açıkta tel kalmayacak şekilde izole ediyoruz. Aslında arkadaşlar projemiz burada bitti sayılır. Bundan sonra flaş devresini kutuya montaj ediyoruz ve kablonun iki ucunu eldivenin uçlarına yerleştiriyoruz. Bu haliyle sistem kullanılmaya hazır. Resim çekme düğmesine basıldığı anda dışarıya çektiğimiz kablonun uçlarında 220 volt ve yukarısında bir enerji meydana gelecektir. Sistemi biraz daha sağlıklı ve işlevsel hale getirmek istiyorsanız bundan sonraki adımları izleyebilirsiniz. 2 mod olarak çalışacak devre için aşağıda bulunan devreyi oluşturacağız.


Ewet arkadaşlar resimde 1 numaralı yer kırmızı led diyotun bağlı olduğu yer. On-off anahatarlardan birini pil ile kamera flaş devresini oluşturan resimde görülen 3 numaralı bölgeye montaj ediyoruz.

Şemada görülen To glove fingertips eldiven uçlarına gidecek olan kablo uçları.


Devreye bağladığımız flipswitch (shack anahtar) kondansatörü şarj etmek için kullanılacaktır bu yüazden her zaman açık olacaktır. Devremizi oluşturduktan sonra proje kutumuza montaj ediyoruz.


Proje kutumuza 4 adet delik açıyoruz. Switch çaplarına göre şekilde görüldüğü ebatlarda delikler açıp montaj işlemini tamamlıyoruz.


Şimdi geldik test kısmına. Devrenin kondansatör bacaklarından çıkardığımız kablo uçlarının birini eldivenin baş parmağına diğerini orta parmağa alüminyum folya kullanarak şekilde görüldüğü montaj ediyoruz.

Devreden sabit gerilim elde etmek için sadece güç anahtarını açmanız yeterli olacaktır.

Devre üzerinde bulunan Led diyot sürekli gerilim var iken yanacaktır. Kondansatör bacaklarında bulunan anahtarın teki sürekli açık olup şarj olmayı sağlayacak. Diğer anahtar ise bir kaç saniye yaklaşık 300 v çıkış vermeyi sağlayacaktır.

Tensions in this assembly reaches over 300 V and are deadly.
			This strobe is made of recovered items in a Fuji disposable camera brand. On the photo-cons, can be recognized mainly: - A. The capacitor whose role is to store energy. - B. The flash lamp. - C. The high voltage required for booting. - D. The step-up transformer. - E. The contact of the flash. - F. The support of the R03. He noted that in this model the high voltage coil, easily visible in this photo, is integral with the lamp flash.
Micro Flash. This strobe is designed for a small dark room. This is an educational project. To realize this setup, you will need: - The structural diagram, - The establishment of pattern components, - The artwork. To print the artwork in scale 1, uncheck the adjustment options in Acrobat. These options are not found in the same place depending on the software version.
		Nomenclature : Resistance Capacitor Diac Triac Diode Flash + HT coil			R1A, R1B R2A, R2B C1 C2 C3 U1 U2 D1, D2 FL1	2.2M 47 k 1 uF or 0.47 uF / 400 V 4.7 uF / 63V 22 nF / 400 V DB3 Z0409 or equivalent 1N 4007 Fuji
		We distinguish the high voltage coil above the lamp on the left picture.
Manufacturing. When the PCB pulled, make the notch for receiving the flash. All holes are initially 0.8 mm in diameter. Then drill the diameter of 1 mm the locations of the diodes, of the triac, the flash and the coil (D). Drill 1.2 mm diameter location of C1, intended for different enclosures capacitors. 1 mm milling spindle location less flash (C). For lamp Fixings: - Drill diameter 2.5 mm the location of the pin (A) - Drilling and milling a slot at the location of the studs (B), - To set up the lamp, pay attention to the presence of clips that must be put in force. When wiring, pay attention to the polarity of diodes that are welded vertically. Applquer a layer of varnish Savings copper side to enhance the dielectric strength of the assembly.
Operation.
The assembly is supplied with a voltage of 230 V AC. Diode D2 performs a half-wave rectification. Capacitors C1 and C3 are quickly charged through R2A and R2B to the value of the theoretical peak voltage that is 325 V (A and B). The capacitor C2 charges through in-R1A and R1B resistance. When the voltage across C2 reaches 32V, the diac (model DB3) becomes conductive. The C2 capacitor discharges by creating a current in the triac trigger (via C, G, trigger, primary coil of the transformer). The triac turns on and the capacitor C3 discharges via the triac power circuit and the primary coil of the transformer. A high voltage pulse is created in the secondary of the transformer (H) which allows the initiation of the flash lamp. The capacitor C1 then discharges in the lamp by creating a flash. The energy provided by the capacitor of 1 uF is E = (C1 x V²) / 2 = (1E-6 x 325²) = 53 mJ (Voltage drops of the diodes are neglected). The power dissipated in the lamp is P = E * f = 53E-3 * 3.33 = 176 mW
When the voltage across C2 reaches the value of 32-10 = 22 V, the DIAC trigger is blocked and the current is canceled. Then off again for a new cycle. With the values ​​of the components of the BOM, you get a flash per second. For approximately three flashes per second, we must change the values ​​for R1A and R1B by 470 k, R2A and R2B by 15k. The role of R2A and R2B is twofold: - Limiting the pulse current charging capacitors C3 and C1 in order to protect the diodes D1 and D2, - Avoid the destruction of the lamp only by the discharge of the capacitor C1. If the mains voltage was positive, there would be no power limitation. Two resistors 1/4 W series is put as even a very low current (R1A and R2A) does not support element 325 V.
				Oscillograms: Calibre of the time base 50 ms / division Amplitude gauge track 1: 50 V / division Amplitude gauge track 2: 10 V / division All measurements were performed with a differential probe, respecting the standards. An unauthorized person has no right to intervene on a mounting supplied with low voltage. For these statements, the component values ​​are: - R1A and R1B = 470 k - R2A and R2B = 15 k Lane 1 represents the voltage across the capacitor C1: The capacitor charges to the through-R2A, R2B, D2 and D1 in the positive half cycle, when the mains voltage is higher than that of the capacitor. Charging is therefore performed in several steps which are represented by the amounts of the curve segments. If the power voltage is smaller than the capacitor, the diode D1 is blocked. The voltage across the capacitor is constant, it is represented by the horizontal segments of the curve. When the triac is conducting, capacitor C1 discharges into the lamp, it is the falling edge of the curve.
It may be noted that the capacitor C1 does not have time to fully charge, the voltage across its terminals reaching almost 300 V. If the stroboscope is disconnected from the mains, capacitor C1 can remain loaded. For an intervention on the printed circuit, the first operation consists in short-circuiting the capacitor. Lane 2 represents the voltage across the capacitor C2: The capacitor C2 charges through in-R2A, R1A and R2B, R1B during the positive half cycle (The load curve is smoothed by the capacitor C3). Charging continues until the diac becomes conductive (32 V + voltage trigger the triac). The DIAC becomes conductive and capacitor C2 is discharged by creating a current in the triac trigger (falling edge of the blue curve). The voltage across C2 fall from a value of 10 V before the diac will re-lock (the typical characteristic is 5 V). The assembly leaves for a new cycle. With these component values, the lightning after every 300 ms.
Lamp characteristics: 1. Dimensions of the bulb: length 22 mm - 3 mm diameter 2. Voltage between anode and cathode: Minimum 200V - 300V Typical - Maximum 350V 3. Maximum Energy for a flash: 15 J 4. Lifespan: 5000 flashes (15 J if one is satisfied with an energy of 53 mJ per flash, real life is several million flashes) 5. Maximum power dissipated in one second: 6 W (P = E xf - In our case P = 176 mW, which increases the lifespan of the flash) 6. Minimum ignition voltage: 4 kV 7. Emission spectrum: 220 nm (ultraviolet) to 2 microns (infrared) with two peaks at 480 nm and 800 nm. 8. Color temperature: 6000 to 7000 ° K Exceeding the maximum caractérisiques 2 and 3 is destructive in the first flash. Exceeding the characteristic 5 destroyed bulb flash in seconds. Version: August 8, 2007

Xenon flashing circuits :

This discussion covers 3 different Xenon flashing circuits from disposable cameras. From them, you will learn circuit tricks that have NEVER been shown in any theory book.  
The first circuit covers 6 BUILDING BLOCKS. 
You will need an old "disposable Flash Camera" plus two extra parts to carry out the modifications. 
No kits are available for any of this discussion. You can get an old camera from a friend or a photographic shop and the parts from an electronics store. The other circuits have different features. So let's start with the first circuit  . . . .

The first circuit comes from a Fuji camera:

You are going to like this project. It costs less than $3.00, contains six BUILDING BLOCKS, re-cycles a disposable flash camera and you are going to learn a lot about electronics.
Everyone has seen a disposable flash camera. Every supermarket, photographic store and corner shop has them near the check-out counter. For less than $20 you get a pre-loaded camera with a flash! It's absolutely amazing technology, but what a waste of resources! After 12-27 flashes, you throw away the camera and a perfectly good flash unit. 
With a little bit of fore-thought, manufacturers could have made the camera re-loadable, but that would defeat the purpose of disposability!
It seems such a waste, to throw away a complete high-voltage flash unit, but that's the cost of progress. 
Well, now you can take advantage of this and pull apart a USED camera. The next time you buy a disposable camera, ask for it to be returned to you when the store develops the film. 
Alternatively you can ask the store to save the next unit that comes in for development - after all, they throw the units away! 
For this project, all you need is a flash unit and two extra components - a BD 679 transistor and a high speed diode. (For a discussion on transistor pin-outs, and finding if the transistor is PNP or NPN, go to: transistor pin-outs.)
You can turn the flash unit into a REPEATING FLASHER CIRCUIT that will flash at the rate of about one flash every 2 or 3 seconds, depending on the quality of the battery. The flash unit draws a very high current and only a fresh alkaline cell will be suitable. That's the only problem with the circuit. It draws a very high current. 
Note: Although the project is written as "XENON Flasher"  the letter "X" is pronounced "Z" as in ZENON. 
The brilliance in technology does not stop with the electronics. If you look at the shutter assembly, you will note it opens the "hole" (also called the pin-hole) as it moves from left to right then closes it again as it moves from right to left.  This allows sufficient light to enter the camera. 
When in flash mode, the shutter opens the hole (by moving from left to right) but the flash has not yet been triggered. The conditions will generally be fairly dark and the film will not been exposed. (it will not have "taken a picture") The shutter then hits the "trigger switch" and the xenon tube flashes immediately. This illuminates the subject and as the shutter closes the hole, the film is exposed. This effectively give s the camera two shutter speeds!  How clever! 

THE BUILDING BLOCKS
This project has 6 separate building blocks: 
1. A sinewave oscillator - more realistically called a feedback oscillator or blocking oscillator.
2. A charge-pump - a diode charging a capacitor
3. A time-delay circuit
4. A relaxation oscillator - not used when in the repeat flash mode
5. A transistor in breakdown mode - this is one of the added components
6. A trigger transformer

WARNING
This project generates 350V DC and stores the voltage in a large electrolytic. This voltage will not kill you, but will deliver a nasty SHOCK! For this reason, the project has a great benefit. It will teach you to work very carefully on equipment with high voltages and if you do get a shock, you will appreciate electricity EVEN MORE! Simply discharge the 120u electrolytic with a screwdriver or jumper lead before working on the circuit. I do. I'm not silly. I don't want to get a bite or tingle each time I pick up or work on the board.  
There is no reason why beginners cannot experience working on this project as it contains non-lethal high voltages and is a very good grounding for electrical safety.  
We forgot to mention the other high voltage produced by the circuit. As you will learn in the notes, a trigger transformer is also included in the circuit and it produces a very high voltage to trigger the Xenon tube to produce a flash. This trigger voltage is approx 2,000 volts but since it is only present for a very short period of time, you would have to be holding the circuit at the instant when a flash occurs, to feel the spike. None the less, this 2kV is part of the circuit and adds to the fact that this project is packed with features. 

THE FUJI CIRCUIT 

1. THE SINEWAVE OSCILLATOR
We start the discussion with the transistor oscillator. It's not really a sinewave oscillator as this infers the output is a nice, clean sinewave.  It's really a blocking oscillator or pulsed oscillator or feedback oscillator or flyback oscillator as the high voltage produced by the secondary winding occurs when the transistor is switched off and the magnetic flux collapses and creates the high voltage in the secondary (also called the tertiary or "overwind") winding. For more details on the operation of this type of oscillator, see our project:
"Making your own 3v inverter." 
The oscillator converts the 1.5v DC supply voltage to a 350v AC waveform. This waveform is rectified by a high-speed diode and charges a 120u 330v electrolytic.
The oscillator consists of three components: 
1. A transistor
2. A transformer,  and 
3. A 220R resistor. 
For an oscillator to work, it must have positive feedback. In other words, positive feedback is a signal that encourages the transistor to keep moving in the direction it is travelling. This can be in the "turning-on" direction or the "turning-off" direction. It's a bit like encouraging a cyclist to peddle harder up hill. That's positive feedback. Then to encourage him to peddle harder down-hill. That's also positive feedback. 
The transistor gets turned on a small amount by the 220R resistor on the base. Current flows through the transistor and also the winding connected to the collector. This is called the primary winding. The primary winding produces magnetic flux and the important thing to remember is the flux is EXPANDING FLUX. In other words the flux is getting stronger (or more-accurately: MORE LINES OF FLUX ARE BEING PRODUCED - THE FLUX-LINES ARE CLOSER TOGETHER). 
This flux passes through all the turns on the transformer and a voltage (and current) is produced in each turn. There are three separate windings on the transformer, (we really say the current is available as a current cannot be measured until is it actually flowing):
1. The primary winding
2. The secondary winding, and 
3. The feedback winding. 

The feedback winding is connected between the 220R resistor and the base of the transistor. When the transistor turns on, the voltage produced in the feedback winding ADDS to the voltage supplied by the resistor and this turns the transistor on MORE. 
The transistor keeps turning on HARDER  until it cannot turn on any more. The flux in the transformer is a maximum but it is not EXPANDING FLUX. It is called STATIONARY FLUX. Stationary flux does not produce a voltage or current in the other windings and thus the voltage and current produced in the feedback winding ceases to flow. This causes the transistor to turn off a small amount and the magnetic flux in the transformer is REDUCED. This flux is now called COLLAPSING MAGNETIC FLUX and it cuts the turns in the transformer and the voltage it produces in the turns is in the OPPOSITE DIRECTION. 
This is one of the amazing features of a transformer. It will produce an output voltage with positive on one wire and negative on the other, when the magnetic flux is expanding. When the flux is moving in the other direction (collapsing) the output voltage is REVERSED. 
This reverse voltage turns the transistor OFF a small amount and it keeps turning the transistor off until it is FULLY OFF. The reverse voltage from the feedback winding ceases, an the transistor gets turned on again by the voltage and current supplied by the 220R resistor. 
This is how the cycle repeats and the oscillator operates at approx 3kHz. In other words, this action is repeating 3,000 times per second. 

2. THE CHARGE-PUMP  
The charge-pump consists of the secondary winding of the oscillator transformer, the high-speed diode and the 120u 330v electrolytic. 
The secondary winding consists of many turns of wire (I haven't counted them). The voltage from this winding is in the form of a pulse or sinewave with an amplitude of about 350v. i.e: the distance from top to bottom represents a voltage of 350v. This is fed into a diode and as we have mentioned in the previous pages of the course, a diode only allows voltage (and current) to flow through it when the anode is higher than the cathode. You will notice the diode has been placed in the circuit in the reverse direction to the way we have suggested in the theory section. That does not matter, it works exactly the same, except the negative pulses pass through it (because the positive pulse emerges from the other end of the transformer and this is really the pulse that goes around the circuit and passes through the diode in the forward direction) and charge the electrolytic. The electrolytic has been fitted with the positive going to the 0v rail. 
Thus, on every negative pulse (from the top of the transformer), the voltage charges the electrolytic. If you place a voltmeter  across the electrolytic, you can see the voltage rising. It rises quickly at first, then at small voltage increments. This corresponds to the graphs we have covered previously, where the capacitor charges quickly at first, then slows down as the capacitor charges to its full value. It charges quickly at first because the charging voltage is very high and the opposing voltage on the capacitor is small and thus the charging voltage has a lot of "pressure" to get the charge into the capacitor. 

3. THE TIME DELAY CIRCUIT  
The time-delay circuit consists of the 4M7 resistor and 22n capacitor. 
In the original design, these two components form a time-delay circuit to let the user know when the storage electrolytic has reached full voltage. The 22n charges via the 4M7 and when 65v appears across it, the neon lamp produces a pulse of red light. 
 

4. THE RELAXATION OSCILLATOR
The neon just doesn't produce a constant red glow, it flashes at about 1 flash per second. The lamp flashes when the voltage across the 22n reaches 65v and keeps glowing until the voltage falls to about 45v. It then goes out. The 22n charges up via the 4M7 and the lamp flashes again when the voltage reaches 65v.   The 4M7, 22n, neon lamp and 10k form a relaxation oscillator with the voltage across the 22n ranging between 45v and 65v. The 10k resistor prevents the voltage across the 22n falling too low and has an effect on the flash-rate.  If you look at the waveform on a CRO, it will be similar to a sawtooth. We are not using this waveform for any purpose in this project, it just happens to be a very simple way to illuminate the neon lamp with the least possible energy, so the main circuit is not "bled" of too much energy. 

5. THE TRANSISTOR IN BREAKDOWN MODE
Our project takes advantage of the fact that a transistor will breakdown when sufficient voltage is present across the collector-emitter terminals and restore its high impedance when the voltage is removed. 
We have added a second high-speed diode to the output of the transformer. This has been done to pick up the positive pulses from the transformer. 
the purpose of this diode is to charge the 22n as fast as possible to a very high voltage to breakdown the transistor connected to the primary of the trigger transformer. The transistor happens to be a darlington type but this is not necessary. Almost any transistor will perform however its current-handling capability needs to be high die to the heavy spike of current delivered by the 22n to the transformer. 
The point at which the circuit "triggers" or "fires" depends on the breakdown voltage of the transistor. The transistor is rated at 80v between collector-emitter but the actual breakdown effect does not occur until about 280 - 300v. 
We need to get the voltage up to this value as soon as possible so that the trigger transistor will "fire" and ionise the tube ready for a flash. 

6. THE TRIGGER TRANSFORMER
The energy stored in the 22n capacitor is passed to the trigger transformer when the transistor breaks down. The 22n will have about 300v across it and this voltage is delivered to the primary of the trigger transformer via the BD 679 transistor. The secondary has a large number of turns and the transistor delivers a pulse of energy to the primary. This pulse of energy lasts only a very short period of time and the magnetic flux builds up and collapses. The collapsing flux produces a very high voltage (approx 3,000v) in the secondary and this is passed to a plate at the back of the Xenon tube (in our case the reflector is the "backing plate" and it effectively ionises the gas in the tube by generating a voltage gradient between the outside of the glass tube and the gas inside and it becomes a very low resistance. The 180v on the electrolytic is also on the ends of the tube and the energy in the electro is instantly delivered to the tube. The result is a brilliant white flash. 

MORE ON THE "CIRCUIT" 
Unfortunately this project cannot be left in a "ready" state as the circuit consumes about 250 - 300mA just to keep the electrolytic charged and a single cell will last only a few hours. Once the electrolytic is charged, it will remain charged for a long time, provided the neon tube is taken out of circuit, as it "bleeds" off a small current through the 4M7 and will keep flashing until the voltage reduces to about 100v. If you can design a circuit to turn the oscillator on and off, to keep the electrolytic charged, it can be kept "ready."
Otherwise it will have to be "fired up" every time it is needed. This will only take about 15 seconds or so and it can be used in an alarm project to indicate when the alarm has been triggered.  Normally a blue strobe light is used, but the circuit can take its place, provided the supply is kept to between 1.5v and 2v.

DIFFERENT CIRCUITS
Unfortunately not all flash units are the same. Our flash unit was taken from a FUJI camera and even different model cameras may have a different circuit. 
The only thing you can do is try the modifications outlined in this project and see if they work. Otherwise you will have to carefully get the circuit off the board and compare it with the one we have drawn. The basic operation of all flash units is the same. One of the possible differences is the positive or negative charging of the storage electrolytic. 

GETTING THE CIRCUIT  "OFF THE BOARD"
If your flash unit does not work after you have added the transistor and resistor, you will have to check to see if it is the same as ours. 
This will involve getting the circuit off the board. This is not easy and not difficult, it just requires a lot of patience and care. 
There are two things you need to know before starting - to make the process much easier - the symbol for each component and an approximate layout for the diagram. In this case the layout and components will be almost identical to the circuit we have provided. The only difference may be the orientation of the high-speed diode and electrolytic. If these are around the other way, the switching transistor must also be placed around the other way. 
You can start anywhere on the board. Turn the board back and forth to make sure you can see where the leads are going through the board and follow the tracks from one component to another.  Check everything over and over to make sure you haven't made a mistake. It's so easy to think a track connects to a particular component whereas it connects to an adjacent component. 
If you don't know the symbol for a particular component, sketch its outline and draw the leads on the sketch. Later you may be able to identify the device by the value of the surrounding components. 
 

POWERING THE FLASH UNIT
If the flash unit is powered by an external power supply, you will have to keep the voltage between 1.5v and 2v so that the oscillator transistor is not over-driven. 
With many types of electronic devices, the circuit will consume a considerably higher current if the voltage is increased slightly. This is due to many factors, one of which is the saturation of the transformer when a higher voltage is applied. The higher voltage will cause a higher current to flow and this will produce a higher flux density. The transformer may not be able to accept a higher flux density and the result is additional current is drawn by the circuit. The higher current may damage the transistor. 
In addition, the higher voltage will produce a higher "back voltage" (called back emf) and this voltage is in the form of a spike that can puncture the transistor. In fact a "power transistor" is more likely to be instantly damaged by a spike than by overheating. 
If you want to add a larger cell, the most economical cell is size "D" (called the normal torch cell). Placing two or more cells in parallel will increase the time the circuit will operate. 
Fitting a 6v battery and using diodes or resistors to drop the voltage is a very uneconomical way to power the circuit. You will get no more life out of the four cells in a lantern battery than using a single "F" cell. 

USING THE PROJECT 
The project can be used as a "dummy camera" to scare intruders. Using a mercury switch on the input, (or an ordinary switch) will turn the unit on. 

A RELATED PROJECT
If you like oscillators and high voltage, a similar project is: "Making your own 3v Inverter." It is a 3v inverter that produces a high voltage (approx 120v) to drive an electroluminescent panel or length of electroluminescent "rope" or "string."  More details of this project can be found HERE.

CHANGING THE FLASH-RATE
One of the requests for this circuit was to increase the flash-rate. The order came to Stelar Laboratories to supply 70 flashing Batons for the Gay Mardigras. The Fuji circuit was the best of the three circuits to use as it has the fastest charge-circuit and the flash rate was increased by reducing the value of the reservoir electrolytic. By reducing the capacitance of the main reservoir electrolytic, it will be charged faster to the level detected by the neon and the flash-rate increases. We simply put another 120u in series with the first electrolytic to get 60u. 
It is interesting to note that the 4M7 charging resistor can not be decreased below 2M2 as the circuit will stop working.
Why is this?
The reason is simple. The trigger transformer relies on receiving a pulse of energy into the primary and the collapsing magnetic flux produces the high voltage. 
If the feed resistor is too low, a current continues to flow in the primary and the magnetic flux does not collapse!
 Photos to come for this article!

CIRCUIT 2:     THE KODAK CIRCUIT
The next circuit we will study comes from a Kodak camera. This has a number of very clever features.  Firstly, the circuit is an automatic charger. It charges the 120u electrolytic then switches off. This increases the life of the battery considerably as the circuit is only powered for 15 seconds or so for each picture and there is no need for an on-off switch. The switch on the circuit is a "start" switch. The circuit also charges up the electrolytic again, after the picture is taken, ready for the possibility of another photo. This action occurs merely because the circuit is "upset." The camera actually gets left with the electrolytic fully charged and it is gradually discharged through natural internal leakage. 
We can only describe the circuit "in general" and cover some of the clever features because the actual operation of the circuit (its efficiency, for example) is a product of the the size of the transformer and the gauge of the windings (especially the primary winding) and the characteristics of the transistors. Some types of transistor work better than others and this may be due to current handling ability or maximum operating voltage (zener properties) or the gain of the transistor.
For example, this circuit takes 4 times longer to charge a 120u electrolytic to 260v, than the first circuit,  due to the transformer being much smaller, (the primary winding is much thinner), and the frequency of operation is much lower.
The supply voltage is 6v and the current consumption is about 300mA. 
A high supply voltage has an advantage. The supply rail can fall a certain amount before the performance of the circuit reduces.  In addition, the current requirement from each cell is less. 
For a 1.5v supply rail, the voltage cannot drop by more than 0.5v before the performance of the circuit reduces. 
In addition, the 1.5v circuit draws over 1 amp when a low-impedance cell is connected. An alkaline cell is a low impedance cell (it can deliver a very high current) and the flash rate is noticeably higher when this type of cell is connected. 
All of these circuits are intended for intermittent use and the current requirement is of little concern, but if you want a circuit to use most of the energy of a cell, the current consumption must be kept as low as possible. 
All battery ratings are taken at a few milliamp (for AAA and AA cells the current is between 10 and  50mA) for C and D cells the current is about 100mA) and the cell is only used for a few hours per day then rested. When the terminal voltage of a cell falls to 0.9v or 0.7v the test is terminated. The multiplication of the current and number of hours of operation is multiplied together to get the amp/hr capacity. 
You can see that these represent very light duty and if the requirements are increased, the capacity of the cell is reduced.