Voltlog #128 – LM338 Constant Current Regulator Circuit

Welcome to a new voltlog, today we are building a very simple constant current regulator based on the LM338 linear regulator. This is a very robust and stable classical regulator that is being manufactured by many big names like ST and TI, it has quite a high output current  rating of 5A continuous, it even comes in a TO-3 can package but today we’re going to use a TO220 which is more commonly available.

To make a constant current regulator out of this, is very simple, the datasheet gives us the circuit we need to use and we only need a low value resistor to do that plus the optional input bypassing cap which is 0.1uF. We’re going to use this formula to calculate the value of the resistor, so the output current is equal to the Vref divided by the value of the resistor.

External references:


Voltlog #112 – The nicest PCB ruler (with microwave components)

Just a short video showing you the nicest pcb ruler I’ve seen so far. It contains the most common microwave components that you will find in an RF design.

Link to this pcb ruler 

Voltlog #100 – InTheMail

Welcome to a new voltlog, today we are taking a look at my electronics mailbag items and it’s episode number 100 so I would like to take the time to thank you guys for your support. Every view like & share I get from you motivates me to continue producing these videos.

Here are links for all the items shown in the video in their order of appearance: