The latest gadget we’ve got in the works here is a modular DC programmable load. The idea is simple: take a bunch of mosfets, some opamps and a DAC and you’ve got yourself a massive power hog. Our design uses relatively cheap irfp260 mosfets instead of special(and expensive) linear rated fets. The ideea is to […]
We managed to snatch an old(1983 going by chip date codes) HP 3456A 6.5 digit DMM off ebay recently. It arrived quickly and well packed from Italy but when I turned it on I was greeted by a display showing 6 dashes instead of a measurement. So I went through the manual to see if […]
We continue on our temperature related adventures with a whopping 64 channel DS18B20 datalogger… This is another 100% in-house build(except for the chinese DS18b20 sensors of course). The basic idea is that these 1-wire sensors can be addressed by a 64 Byte GUID which allows you to hook up as many as you’d like to […]
Here we brag about or USB PT1000 temperature sensor. The board was build in-house(notice the bodge wires) and uses an STM32F0 with integrated USB peripheral to talk to an android phone and report the sensed temperature. This build measures the resistance of the sensor using a Wheatstone bridge(back of the board). In order to get […]
Our little CNC mill did a great job on our homemade resistor box and the keithley agrees! We used 0.1% tolerance, low tempco resistors for a total of 7 decades from 1 ohm on the lowest decade to 1 MΩ on the highest. The all plywood case features box joints on the corners made on […]