Recent content by Ken Freeman

To address whether the 2N2222, is suitable for your use, we need to understand your voltage and current requirements, and your switching timing requirements. How frequently is a full transition required (from on to off to on)? Is there a requirement for how fast a turn on must be completed...

What does the static or noise sound like?

What's it called? Some brief Googling is turning up a wide range of stuff, not obvious if they're what I'm thinking of.

Maybe you can start by describing the "selectable voltage DC adapter," and the "home audio device."

One problem in predicting RCS is the irregularity and complexity of real objects. In my previous job we obtained measurements of the RCS of several different cars on a turntable, full circle at 1 degree increments. The variation in RCS was in some cases more than 10 dB in adjacent bins...

When I hear of a noise problem, I think of all the potential noise causes and coupling methods, and try to gather the information I would need to narrow down that list. If that looks too complex to you, that's your lack of perspective. It's also false to look at a problem as complex, then when...

I'd start with Wikipedia. There are a bunch of different types of electrical machines. As motors, torque is generally increased by feeding it more current, and that current is forced by higher voltage. But there are safety ratings that should be adhered to. If you violate them badly enough...

I just joined, and I'm a power electronics and motor driver designer. It's too bad nobody helped you here.

I think one thing that's missing in both design exercises is a good analysis of the bus/other vehicle mission profile: speeds, accel/decel, climbing delta-H and climb speed, and find out what is actualy the reason for the necessary propulsion torque and power, and at what road speed. The...

I think you said at the outset that the 4 amp pulses resulted in a voltage drop of just a few volts. I doubt that would cause an easily noticeable flicker in an incandescent light. (By the way, is the light actually pulsing on and off, or is it a very subtle flicker?). You can test this by...

actually there are a lot of ideas, but none are simple. One possibility is that your TEC is shot. I don't think your current pulses are what's causing the flicker on incandescent bulbs, because a 3 or 4 volt drop is really not very much. You don't know that noise problems are inherently...

Generally AC motor speed is synchronous, meaning it spins at a speed determined by the 60 hertz line frequency. To double the speed you'd double the frequency. To double the frequency you need to connect an electronic device called a cycloconverter between the motor and the 60 hertz power...

Your power factor question is a very good one. Will GE tell you what the nominal power factor is? Does GE recommend or provide any ancillary equipment to filter the input, suppress line noise, or ensure that the cooler power factor is benign? Overall I suspect the problem is due to...

The answer to your original question is not simple. People are asking you for more information in order to better understand your problem. Engineers usually do not "just know" the answer, we rather have skills at diagnosing situations and developing an explanation. Usually the first step is...

I agree with the need for an auxiliary start-up power source. An initial view of an overall power processing strategy for your system needs is as follows: Create an inverter of some sort to chop the source current and drive the primary of a specialized transformer, designed to carry such a...