This video checks the accuracy of the UNI-T UT658 USB Tester and discovers some issues and quirks you may want to know about. The UT658 is not always showing what is really going on. It measures volts reasonably accurately (albeit its update rate is quite slow) but the amps values are not as good. Also the battery capacity metering function can be fooled. ... https://www.youtube.com/watch?v=K7UxnF6LZtU

This video is about the vintage Racal Dana 9300 RMS Voltmeter. It is a highly sensitive meter to measure AC voltages from 30 uV to 300V at frequencies of up to 20MHz and beyond. You can pick up for very little money and well suited to be integrated with digital meters. The VISHAY capacitor part number for the 2200uF 50V type I used is MAL214651222E3 The replacement R14 is a 560 Ohm 1% metal film resistor TE-connectivity part LR0204F560R You can support the channel by becoming a patron. https://www.patreon.com/user?u=45604138 As a patron you get early access to all my videos as well as exclusive content. 00:00 Comparison 04:59 DC out 06:06 Inside 08:07 Cap replacement 09:03 Function 12:44 9300B 13:10 R14 replacement 14:41 Test 15:20 Cal problems 18:28 Usage 20:51 Conclusion PIC frequency counter mod: https://youtu.be/0BxpMm6SLoE (be sure to look at the whole series of my videos on that counter) ... https://www.youtube.com/watch?v=xqUcDiZcMTg

This water timer is currently (beginning of August 2018) on offer. In this video, I take it apart as far as possible and do some measurements of current consumption and how far the voltage can drop before the unit goes into low battery mode. I am also explaining how to program the unit and what the settings do. Overall, this is a very nice water timer and seems to be quite well designed. The instructions are good and the operation is very easy and straight forward. I like it and its now installed outdoors in the garden. ... https://www.youtube.com/watch?v=AU8Qk5pir24

My current project uses panel meters and is taking longer than expected. So I decided to put up a video on my experience with these cheap eBay panel meters, in particular how to power them safely and how to use them to measure voltage and current in power supply that has a positive and negative rail. 00:00 eBay panel meters 00:50 2 and 3-wire meters 01:42 Regulator limits 03:19 3-wire test 04:14 2-wire test 04:37 construction 05:56 simplified schematics 07:04 wiring scheme 07:37 getting a safe supply voltage 10:31 use with pos & neg rails 11:29 current accuracy ... https://www.youtube.com/watch?v=PCwxSXlXzlo