Hi.
Regarding the 'Speed-Matic' rotary tool.
I've had this 'As-seen-on-TV' mini-drill / rotary tool several years, rarely used these days.
I mislaid or lost the original wall wart that came with the kit.
Did not realize the rechargeable cells have been leaking electrolyte.
Now want to remove gunky cells and mod to PWM, direct Voltage.
From researching the device, it appears that similar products use a 3.6-3.9 VDC wall-wart as a battery charger, and users have measured about 500 mA no-load and over 3A stall motor current.
Motor Voltage unspecified and my motor un-marked.
The DMM reads DC resistance of 4.3Ω.
Disconnected cells and 100n cer disc snubber capacitor across motor, for R test.
So, if 3.5 A is taken as Imax (stall), and Rmot is 4.3Ω, then is max Vcc 15.05 V?
I plan, if possible, to use 12 VDC, either un-modulated or PWM.
Thanks, Clive.
Regarding the 'Speed-Matic' rotary tool.
I've had this 'As-seen-on-TV' mini-drill / rotary tool several years, rarely used these days.
I mislaid or lost the original wall wart that came with the kit.
Did not realize the rechargeable cells have been leaking electrolyte.
Now want to remove gunky cells and mod to PWM, direct Voltage.
From researching the device, it appears that similar products use a 3.6-3.9 VDC wall-wart as a battery charger, and users have measured about 500 mA no-load and over 3A stall motor current.
Motor Voltage unspecified and my motor un-marked.
The DMM reads DC resistance of 4.3Ω.
Disconnected cells and 100n cer disc snubber capacitor across motor, for R test.
So, if 3.5 A is taken as Imax (stall), and Rmot is 4.3Ω, then is max Vcc 15.05 V?
I plan, if possible, to use 12 VDC, either un-modulated or PWM.
Thanks, Clive.