Lets make this Hewlett Packard, HP 419A DC Null Voltmeter work again! Very useful information regarding the chopper circuit, and how to make it dependable. Also in this video, Mr. C shares his custom designed circuit to replace the original neon chopper board. Click the SHOW MORE tab below to expose links.


To learn more about electronics in a very different and effective way, and gain access to Mr Carlson's personal designs and inventions, visit the Mr Carlson's Lab Patreon page here:   / mrcarlsonslab  

The official collectible 2020 Mr Carlson's Lab Calendar is available now, but not for much longer! Here is the link to order: https://www.bookdepository.com/MrCar...

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