Can I wire the contacts from the charger directly to the switch on the drill to bypass the battery
I'm going to be using the motor from a cordless power drill for a home theatre project (remote-controlled rotating TV), but I would much rather have constant power supply and not have to mess with the cordless drill batteries. The reason I am using a cordless drill is for the 2-speed gearbox (i need low rpm w/ more torque) and the autobrake. My question is this:Can I wire the contacts from the charger directly to the switch on the drill to bypass the battery? If not, what would be the problem/result of this? How can I make this work?
The cordless drill battery service cener answer me:Chargers are current regulated at a safe level designed for the battery. As such, it is not sufficient to run the motor directly, especially under load. A better solution is to find or build a suitable power supply. I would think something with a couple of amps should put you in the game. If you build it, it would only take 3 basic parts -a transformer (with a secondary close to the voltage and current you need), a bridge rectifier, and a modest electrolytic filter capacitor.As to wiring, the power supply should be hooked to the leads of the battery contacts. The leads of the drill's switch would be hooked to whatever actuator you are using with your remote.
I once played with a battery drill - hooked it up to a 12V drill battery for mobile use - and measured about 9A while drilling an 8mm hole into aluminium. You could measure this (best to measure under load, so do it once it's installed and working),You could leave the battery in circuit by connecting the charger to the battery contacts while the battery is in the drill. The drill battery would always receive a charge and would supply the larger current when the unit is occasionally activated. Depending on the quality of your charger, this may cause the battery and charger to get warm, maybe even overcharge the battery. If so, make sure you can switch the charger off; I doubt you'd need to switch in on very often.If all this spells a hobby in dc power, the concept of storage for short term peak loads will be well demonstrated. If not, your theatre will look good anyway.
