[DIYman (Doug)]

Hello all

I want to run my Canon 20D from a 12 Volt battery and also from a mains AC through a 12 volt transformer/rectifier for AP. I need 8 volts output for the camera so the L7808 voltage regulator fits the bill.

Since I plan to run the camera from a transformer/rectifier I will need to fit capacitors to the input and output sides of the L7808 and this is where I need advice.

I checked the Internet etc and keep finding different values and types of capacitors in circuits using the L7808. It’s a bit confusing as electronic theory is not my strong point. I want to do what is correct for my application as I do not want to bugger up the camera’s electronics by using the wrong capacitors (transient spikes etc) especially when using the transformer/rectifier setup.

Some sources show 0.33uF capacitors being used on the input side while others show 220uF. That’s a huge difference - how can this be? On the output side, some sources show a 0.01uf ceramic being used while others even show the use of a (0.01uf) electrolytic capacitor. ????

I looked at the L7808 I bought from Jaycar and apart from a couple of meaningless numbers there is no manufacturer’s name so I cannot search for their datasheet. One web page warned strongly against relying on recommendations from one manufacturer and applying them to another’s device saying this could lead to failure of the regulator and associated circuitry (my camera).

I would really like some practical advice on this issue so I can get on and start using the camera.

Thanks in advance.

DIYman (does not include electronics)