Author Options:

9v VS 9vdc? Answered

I'm working on an LED IR Illumination circuit (KipKay's nightvision with just the LED circuit).
The thing works great but kills my 9v batteries pretty quick.

I have a 9.6Vdc 300ma power adapter.
Is is possible and SAFE to use this in the circuit instead of a 9v battery?

KipKay's Project
Power Adapter



The forums are retiring in 2021 and are now closed for new topics and comments.

9 years ago

Not sure, how good your power adapter is - how good the regulation works - the output voltage might be higher if the load is much lower, but if the circuit takes about the rated current (the 300mA, give or take somewhat) you should be fine.

Measure the output without load. If it is somewhere around 9V (+- 1.5V) you should be fine.

If you don't have a multimeter, it's tricky. I don't get KipKay's project circuit completely, but any way, it should work. 0.6V is not a big overvoltage.


9 years ago

I don't know the load current required for the application and am too lazy to view it, but I CAN tell you a very simple way to strip that excess voltage.

Place a diode in series with the positive terminal of the load

- BAT + ----------|diode >|---------- + load ------ to bat -

If you use a Schottky diode you'll drop about 0.5V. A normal 1N series about 0.7 V

Just make sure the diode can carry the expect load current + ~20%.