using 7806

[nickeevblog10]

Hi, I am a newbie so I better start at the beginning.
I have an AS600 6V alkaline battery powered portable screwdriver and want to power it using an unused computer power supply.
I want to connect the motor to a molex connector and wondering if simply splicing a 7806 voltage regulator between the motor and the molex connector from the computer power supply is going to be enough for the motor to work properly.
I have included photos so you can see what I have done so far.
First I tried to run the motor of 12V forgetting it is a 6V motor then began trying to find out what to do to make the motor run.
I was told splicing the 7805 voltage regulator into the setup would work ok.
I would like to know now not just to to guess, if someone can help me please.
I hope I can get the photos I took to upload.

[djacobow]

This will probably not work. The 7806 is only good for up to 1.5A, and that only when power dissipation it's handled adequately.

The drill motor might draw less than 1.5A when free-running, but when it's actually generating torque turning a screw, I suspect it pulls much more.

Also, dropping 6V @ 1.5A means 9W dissipation in the regulator. Your little heat sink is likely not up to the task.

Finally, you should have some capacitance in the input and output of that regulator.

On the other hand, the 78xx are pretty robust little guys and are more likely to shut down when unhappy than just break, so you might get away with light intermittent use.

[Nusa]

It would depend on current requirements, which may be too high when the screwdriver is working hard. AA batteries are capable of delivering a lot more current than a 7806.

I'd suggest trying it using the computers 5V supply first, since you've got that already. If the performance is adequate, you're done.

[Brumby]

+1 on trying the 5V

The voltage of batteries under load will sag a bit, but the 5V of computer PSUs will be regulated ... and they tend to offer a good chunk of current.

[nickeevblog10]

 Using the computer power supply 5V worked well and when I applied pressure to the motor while driving the screwdriver it handled that really well.
Thank you