RC10Talk - The Net's Largest Vintage R/C Community

OK I bought a couple of totes of RC stuff , a racers stash no doubt .

And I got a few of these doo dads.

I am assuming they are to discharge a battery pack .

I am familiar with the bank of light bulbs discharge bank and understand that part .

Looking at it I can see the big resistor takes off the packs charge , the little one lets the LED light to let you know its working but why that diode is in there puzzles me ?

Did people really want to take their packs down til there was about 5 electrons left ?

Wouldn't this take forever and a day even after the light bulb bank discharge ?

Anyway , the back of the board says BUG and COBR A




Feel free to give a education here

Thanks
Rat

If you were to direct short the pack the voltage would be zero, but some of the cells would be positive and some would be negative, potentially damaging the cell.

The resistor kept the pack voltage from going below, say, 1 volt. That way none of the individual cells in the stick pack would be forced into negative polarity.

Nicd cells have a very quick discharge rate once they dump, so it didn't take very long to bring the voltage down after the pack had been run. An hour or two would usually do it, overnight for sure.

WC1982 wrote:If you were to direct short the pack the voltage would be zero, but some of the cells would be positive and some would be negative, potentially damaging the cell.

The resistor kept the pack voltage from going below, say, 1 volt. That way none of the individual cells in the stick pack would be forced into negative polarity.

Nicd cells have a very quick discharge rate once they dump, so it didn't take very long to bring the voltage down after the pack had been run. An hour or two would usually do it, overnight for sure.

Thanks !

These were called "Battery Bugs". I have several from back in the day. I have no idea why they were called "bugs".