Thread: A warning about inverters

Originally Posted by Wil2k

I got a bit creative and built a battery voltage monitor (Jaycar kit) and added a buzzer to it. I can set the monitor to raise the alarm at a preset voltage, and when it drops below that I get a red LED status light and a small buzzer going off.

I've built the circuit into the space above the cargo are accessory socket and used the blank panel that the rear seat headphones / remotes would occupy in a posher edition. Two small holes, cables directly down to socket. Piggy backed off the existing connectors. easymode!

I looked at a bunch of pre-made options from jaycar and auto suppliers, but this suited me better. LED is easily visible from outside the car, and at the rear (where most camping takes place in my case). Also (in my case) most longer usage of accessories when stationary (eg for camping) tends to be via this socket.

Tested it out, ran my laptop off the inverter for well over an hour before it triggered at a smidge below 12v. Crank battery had no dramas starting again. I'd like to set it more precisely that the trimpot allows though, so i may replace it with a finer range one OR fixed resistors.

Will post pics if anyone is interested. Cost under $15.

G'day Wil2k,
I would be interested in a few pics.

Regards
Maggsie

Originally Posted by maggsie

G'day Wil2k,
I would be interested in a few pics.

Hey Maggsie,

Here are the blurry poorly lit pics I took on my iPhone
One note.. when I added the buzzer, I took the +lead to it from the other side of the resistor in sieries with the LED so that it had enough voltage to operate. Also, in the second hole (for the buzzer to buzz through) I have put a thin piece of cotton cloth between the buzzer and the plastic (a small circle) held in place by the glued buzzer. This is to keep the dirt out of the buzzer, but it also mutes it a little. I may try it without it.

Here's the Kit I used: LED Battery Voltage Indicator Kit - Jaycar Electronics

Originally Posted by Signal1

I ran a lead out to the inverter in the Disco and powered up the modem, router and notebook. She queried where I was getting power? "From that thing in the Disco you think is a waste of money!" I replied.

It's nice to be validated sometimes.

Nice!

cheers