Voltlog #131 – Measuring The Efficiency Of The Ruideng Kis3r33S DC-DC Converter

You might remember this small module from the previous InTheMail, this is the Ruideng dc-dc converter with a claimed efficiency of 95%. Now a figure of 95% efficiency is not unheard of these days, many dc-dc converters can achieve this with proper circuit design.

This particular model uses the MP2307 converter chip manufactured by Monolithic Power and if we take a look at their datasheet we can immediately see where they got the 95% efficiency figure they advertise.

If you own fancy equipment like a source/measure unit than one instrument can do all the measurements and data log the results as well but a source/measure is out of our budget so we will be using multimeters for this test.

Here are links where you can find the equipment used in this video:

Voltlog #34 – Fluke 77 Teardown & Repair, Varistor Replacement

In this video I’m opening the Fluke 77 I scored at a recent auction to show and repair a small issue it has. One of the MOV (metal oxide varistor) in the input protection circuit had suffered damage probably while protecting the rest of the circuit when a HV signal was applied to it’s input, so I decided to replace the MOV.

The original MOV part number is V910LSX1399 specs: 910V 10% 1mA
The replacement MOV part number is Panasonic ERZV10D911 specs 910V 1mA