Here's how to make a good $3 Gauss meter, for anyone who's interested. The AD22151Y chip (pdf datasheet) is a linear magnetic field transducer that cost $3. Amazingly enough all you need is ONE resistor to make it work for a gain of one, and that includes the ability to measure magnetic fields of both polarities ...
2010-10-02 14:56:06
The meter now data logs everything, power input, both power outputs, input voltage, both voltage outputs, input & output current, and efficiency. When the meter is turned off, and then back on again, it begins data logging where it left off, so it never overwrites any data. That is, unless you select reset all, in ...
2010-09-12 19:58:38
Lots of bugs were fixed due to the data logging software additions, but as of last night it was looking good. Just a few more minor software changes is about it. The Hue efficiency & power meter now logs every efficiency measurement to the SD drive. Also there's a mode (pressing down on joystick) where the meter ...
2010-09-11 15:22:42
All of yesterday was spent on making the Hue efficiency & power meter linear at low levels, and also adding more software features. Wow, the efficiency & power meter is now scary linear. The software additions are going crazy, perhaps too much. They're almost finished though. One addition is a data logger, ...
2010-09-10 14:10:56
The later part of yesterday and all of today was spent on getting the Hue efficiency & power meter linear at low levels. The problem ended up being very simple. My method of setting the software offset was wrong because of the instrumentation amplifiers common voltage. For like weeks I've been battling with the ...
2010-09-09 20:17:57
Most of today was spent on getting my car brakes done. A neighbor who owns a car dealer gave me an offer I couldn't refuse. Part of today was spent on fiddling with the op-amp circuits for the Hue MCU efficiency meter. It only requires a POT to balance the differential op-amp circuit that will measure the current, but ...
2010-08-28 04:34:35
I was just about to put on my ESD wrist strap when it occurred to me that I've never mentioned this before. For newbies, when working with IC's, espcially components that have FET's, you should make an attempt to wear an ESD wrist strap. ESD stands for electrostatic sensitive device. You place the strap around your ...
2010-08-26 20:57:57
For years I've tossed around the idea of making an oscilloscope card for a PC, no MCU. For example PCI Express 16X slot can achieve 16 GBytes per second. That's 128 Gbps (128 billion bits per second). The downside is that such a design can be a nightmare, and debugging it is even worse. My hats off to anyone PC card ...
2010-08-24 14:51:46
Hopefully within a week I'll put together a post containing all of the code and tips so that anyone could easily get the Olimex MSP430F169 dev board with LCD screen, SC card, ADC's, and DAC's all up and running in no time with the free open-source mspgcc compiler and Olimex JTAG programmer. That should save anyone new ...
2010-08-19 23:25:57
The MCU capacitor tester now displays the capacitors capacitance. So now it shows the capacitor efficiency and capacitance. What's interesting is that the manual capacitance measurements I made 4 days ago (very rough figures) on the 40000 uF capacitor that showed the capacitor at 80% efficiency was based on the ...
2010-08-15 22:01:10