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.

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Voltlog #28 – InTheMail

In this episode I am showing my latest mail items which include: a bunch of Vishay-Dale shunt resistors which I got for a bargain price, different sizes silicone wires, ultrasonic sensors, a voice recorder, the st-link v2 programmer/debugger, dmx512 decoder board for driving rgb leds, rs485 to ttl converter module, a pair of 433MHz ASK transceivers, some thermal plaster, a metal marking/punch tool and a hiking monocular.

Links for the products shown in this video: