Recent content by jgershonw1

Is is possible to switch the tap of a transformer without interruption or shorting? Ideally, the mcu is controlling the tap and being powered from the same transformer. Any ideas?

I want to make a voltmeter that can measure from 0-25vdc using the ADC. Right now, I am using a resistive divider to scale the voltage down to measure +'ve voltage. But, how do I handle a negative voltage when the measuring leads are reversed? I did some searching and it appears that an...

I am making a rain detector using a leaf sensor. Basically it's a pc board with closely spaced parallel traces, which starts to conduct when it's wet. To make it effective, I want to heat the backside of the board to dry the detector/trace side. The board is approximately 2x4 inches. Any...

I need to simulate a revolving light for a model lighthouse. I know you can dim and brighten a single light to simulate this effect. But, this is not good enough because I want the light to be somewhat directional. To complicate matters, I only have a 2cm diameter area to work with. One way...

Awhile ago, there was a discussion about the Hoperf HM-TR. I bought a batch of the 232 version. Now, I want to convert some of them to TTL. The datasheet (http://www.hoperf.com/pdf/hm-tr.pdf) shows the two versions side by side and I can just barely see the differences. From what I can see...