HP 65 Card reader task

[teenix]

The rubber band and battery is probably the safest, but from a power supply, set it to 3.75 volts.

The motor should draw about 180mA. If you have a variable output power supply with a current meter, you should see the change when the motor is running.

If you have a multimeter with current reading capability, then just connect it in series with the power supply +ve output. Meter positive to supply positive, meter negative to hp-65 bottom +ve terminal and power supply -ve to hp-65 top -ve terminal.

All the pins I mentioned are on the sense chip, be careful not to short any pins with the probe.

There is an indent at the centre top of the chip. pin 1 is directly to the left, down to pin 10, across right to pin 11 and up to pin 20.

http://www.hpcc.org had circuit diagrams by Tony Duell, but I can't access the page.

cheers

Tony