Anyone have a cassette motor off a 15v (10-"D" cell) deck that they can spare, perhaps on an unused parts unit someplace? I need one badly.

what box is it for

It's for a Panasonic RX-5350.

Whats the voltage on the motor say?
12 volt motors will work at higher
voltages anyways.
They have a voltage 'range'
so they will work at lower and higher voltages.

The ID on motor is:

MMI-6A5HKPD
15V CCW.

If a 12v motor is operated at 15v, will the speed be too high? I've also noticed that on most boomboxes, the system when operated on AC is higher than battery voltage. In other words, a 12v boombox might show 13.5 volts at system rails when operated on A/C and 15v box might show 17.5 volts.

i might have what you need. give me a minute to look

Sinister: Any luck finding one? You'd make my day if you have one....

so far i have whats looks to be an 11v motor but i dont know if its ccw. i have one more parts box to check i will do that now

i have a working M90 motor. dont know what voltage it is. or the direction


and last i have a 12v motor but again not sure if its ccw

Use an standard 12V motor with a 3V zener in series (to get a 3V voltage drop) and you are done. Use a 1W Zener at least.

Are you sure? That seems like an inappropriate use of the zener diode and you will be getting a 12V voltage drop (minus any voltage drop across the motor) and the entire current consumed will flow through the zener diode.

It seems that for a 12 volt regulated system, you would use a 12volt zener which is installed in PARALLEL to the regulated load, all in series with a power resistor sized to provide some current limiting. The zener installed in this way provides the voltage drop and regulates voltage, the resistor limits the current through the system and provides additional voltage drop...

"......Zener diodes regulate voltage by acting as complementary loads, drawing more or less current as necessary to ensure a constant voltage drop across the load. This is analogous to regulating the speed of an automobile by braking rather than by varying the throttle position: not only is it wasteful, but the brakes must be built to handle all the engine's power when the driving conditions don't demand it. Despite this fundamental inefficiency of design, zener diode regulator circuits are widely employed due to their sheer simplicity. In high-power applications where the inefficiencies would be unacceptable, other voltage-regulating techniques are applied. But even then, small zener-based circuits are often used to provide a “reference” voltage to drive a more efficient amplifier circuit controlling the main power....."

Thinking this through, I believe it's best if I can find a 15v motor instead....

What you really need is a voltage drop of 3V to feed a 12V motor from a 15 supply.
If the zener has a zener voltage of 3V, when biased as a zener, a 3V drop would occur across it.

Don't get confused with zener-based power supply regulators or easy to made supplies with paralell zener. I'm not telling you to built a voltage regulator. Only use the zener to get a voltage drop.

It's the same as putting about four or five general purpouse diodes in series (like the 4007). You will get a voltage drop across them of about 3V enough to lower the 15V to 12V.

All the current will flow across both, motor an zener.

Normal operation current for a motor is around 150mA, so 3*150mA about 1/2W zener. But put a 1W one ... currents are likely to raise a lot in soft touch mechanisms when enganging.

Pedro, knows what hes talking about. he has helped me a few times and has been right

I get where you're coming from now. Diode installed in reverse direction in series, rely on zener voltage drop... instead of creating a regulated supply. I'm going to try this if I can't find the motor I need. Thanks.

I have used the 3-pin voltage regulator
to do this too.
I did it in a car stereo
used a 9 volt motor
and 9 volt regulator.