T&L Publications

Hello everyone!<p>In the January 2001 issue of Nuts & Volts there was a DC motor speed controller based on a PIC12C671 driving a single MOSFET (ref IRL540). The text says that the controller can handle up to 28 Amps and 18 Volts.<p>I am working on a similar project, but the main voltage will be 24 Volts. I have looked up the specs for the IRL540 and it does say that the max continuous current is 28 Amps. However, I cannot find any voltage limitation that I can understand. In other words, it does not seem to be limited to 18 Volts.<p>So, can I use the original speed controller with a 24 Volt supply or is there something in that design that would prevent me from doing so? (and what is it?)<p>If the answer is no, please suggest modifications in the design or a different MOSFET.<p>Thank you.

The spec you are looking for is V(BR)DSS. The datasheet says 100 volts, so you should be OK. I haven't seen the article, but I'm assuming the gate is driven by a 5 volt logic level. The IRL540 cannot take more than 10 volts gate-to-source.<p>Ron H

Thank you Ron!

Is there a way I I cud get a copy of this article? Id be real interested in building an esc for a small 15 amp motor... rc airplane...

You can buy back issues. Go to http://www.nutsvolts.com/backissue.htm<p>Ron H

Well, I'm here because contrary to my better judgement, I decided not to build the circuit described in the magazine I decided to test my motion control with a commercially available DC motor speed controller. the first few rounds went OK but then my 8051 controller board went up in flames. The manufacturer of the board said that my signal isolation was the culprit and I do not know enough to argue back. So, would anyone please tell me what is signal isolation and whether I could build the circuit to drive a 90volt 5.5A motor with stop and reverse?<p>Thank you in advance