DIY Fan Speed Control

[Bryan]

Delphinus:

I haven't built one yet so I can't give you a price per chip. But I have noticed it's not a very common IC and could be hard to find.

Stephane:

No, I haven't built one yet. Upon closer examination it appears this chip is designed for computer power supply fans. Here is a quote from the PDF file. Looks like the max fan current is dependent upon the tranistor. the recommended transisitor can handle 400ma. As for the PCB the circuit is so simple you could build it on solderable breadboard. If interested you can pop over to www.canada.digikey.com for mail order electronic parts.

I think someone on this board is a electrical engineer. If they are listening any thoughts on this IC.

>>Transistor and Base-Drive Resistor Selection
The OUT motor-drive output, pin 7, is intended for driving a medium-power device, such as an NPN transistor. A rather ubiquitous transistor, the 2N2222A, is capable of switching. It is also available as the PN2222A in a plastic TO-92 package. Since 400mA is about the maximum current for most popular computer power supply fans (with
many drawing substantially less current) and since the MIC502 provides a minimum of 10mA output current, the PN2222A, with its minimum β of 40, is the chosen motor-drive transistor.<<