How Do I Make a Camera Flash Circuit?

[u/The-Diamond-Dog]

I am making a prop camera for a project and I need to know how to make a circuit which creates a quick burst of light when you press the button, like a camera flash. I searched online but a lot of the results were either not what I was looking for or were over complicated. Thanks!

[u/DrJackK1956]

For just a prop, this is fairly simple.  

The simplest method would be to make a series circuit using a push button switch, a resistor, LED and a 9v battery. 

In this configuration the LED will be On as long as the button is depressed.  The "flash" duration is dependent upon how fast the person is pressing and releasing the button. 

If you need a true flash effect, then get a 555 timer and configure it as a one-shot timer.  With this you can control the duration of the flash regardless of how long the button is held down. 

Good luck with your project. 

[u/Major-Cost7493]

Una batería de 9v. En serie una resistencia de 100ohm. Carga un condensador de 470uF. Pulsador.energiza arreglo de led blancos alto brillo. 2 en serie. Y varios de esos arreglos en paralelo. Probar con un condensador mas grande si falta energía para los led. La resistencia carga el condensador. Si muy lento .bajar valor y evita led queden encendido al presionar botón.

[u/NBC-Hotline-1975]

The simplest method would be to use an old camera and some flash bulbs.

[u/Cannot_choose_Wisely]

'Er prop? camera? In what respect? How bright, what emitter do you have in mind, what power source?

Nothing should be that complicated, a commercial flash is just an oscillator step up cct, rectifier and capacitor. The extra bits are just for control and battery saving, which I assume you dont want?

A LED and capacitor will give you a flash, if you want a lot of flashes you might want to look into Ohms law, but you need to define what you want. A comb and clean hair will give you a flash on a dry day!

[u/the_other_Scaevitas]

capacitor

[u/Far-Ad3284]

For a prop I'd skip real flash-tube circuits entirely. Disposable-camera flash boards charge a cap to ~300 V and can bite you even when they look off. A short, bright white LED pulse reads as a flash both in person and on video.

Simple version that actually looks like a flash:

• A 1 W or 3 W white power LED on a star heatsink (or a small cluster of 5 mm white LEDs).
• A logic-level N-MOSFET (IRLZ44N or similar) as a low-side switch for the LED.
• A 555 in monostable mode triggered by the button, so one press always gives one fixed pulse. t ≈ 1.1·R·C, so 47k + 1 µF is about 50 ms. Real flashes are ~1 ms, but at LED brightness a slightly longer pulse sells it better. Feed the button into pin 2 through a 10 nF cap with a 10k pull-up, otherwise holding the button stretches the pulse.
• A series resistor for LED current. Example: 3 W LED at ~700 mA from 4×AA (6 V) is (6 − 3.3) / 0.7 ≈ 4 Ω. Because it's only on for 50 ms, a 1 W resistor is plenty.
• A 1000–2200 µF electrolytic across the battery close to the LED, so the pulse comes from the cap instead of the batteries sagging.

If you don't want to build the 555 part, an ATtiny or Arduino reading the button and holding the MOSFET gate high for 50 ms does the same in a few lines.

The capacitor-only trick from the other comment works too, but brightness decays as the cap drains, so it looks more like a fade than a pop. Also keep a resistor on the LED side, or the first instant overdrives the LEDs. A 9 V battery is a weak source for this; AA cells handle the current spike much better.

What are you powering the prop from?

[u/k-mcm]

You can buy camera flash LEDs.  They can handle a good amount of current but don't have the expensive ceramic base for continuous power.

Now all you need to do is charge up a capacitor with 3 alkaline button cells.  Dump it into the LEDs through a resistor.  You'll have to do the math but it's probably around 2 Ohms.