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Showing posts with label LM2596 DC-DC Adjustable Voltage Module. Show all posts
Showing posts with label LM2596 DC-DC Adjustable Voltage Module. Show all posts

LM2596 DC-DC Adjustable Voltage Module:

 LM2596 DC-DC Adjustable Voltage Module, useful addition for all manner of voltage conversion requirements for a DCC garden railway.

As a practical alternative to the usual L78xx Linear voltage regulators, the LM2596 unlike the Linear voltage regulator alternatives, do not suffer the thermal runaway issues, that  arise from converting the excessive voltage inputs, to heat. 

Readily available, economical, fairly robust, and generally reliable.

Whilst advertised as being able to supply 3 Amp, would suggest to increase reliability and longevity of the module to keep to around 1.5 Amp in continuous use, for short term use 2 Amp is acceptable.    

A few quirks and anomalies can occur from time to time if the input sourced supply voltage is from a DCC system. 

From time to time, it is rare it has to be said, on a DCC system, the circuitry of the LM2596 module can go into oscillation, which causes havoc with the User predefined output voltage, not good!, especially if the regulated output has been set at 5V for instance for a Logic Circuit, and the LM2596 module goes into free fall and puts out for example 22V through the output!  

The cure is simple, as a 104 Capacitor soldered across the voltage inputs IN+ and IN-.

To increase speed and efficiency, consider replacing the often quoted standard Bridge Rectifier, with a Fast Recovery Bridge Rectifier.

LM2596 DC-DC Adjustable Voltage Module

LM2596 DC-DC Adjustable Voltage Module Info

LM2596 DC-DC Adjustable Voltage Module for daily use, for testing etc.

Purely by chance, the original idea was to replace the Turn Screw 103 10K Potentiometer, with a standard one with a knob, for easier adjustment.

Consulting the schematic above, the voltage output is regulated by the 3.3K Ohm resistor, and the adjustable 10K Potentiometer.

By removing the 10K Potentiometer, and soldering in its place a 1K Resistor, now have a fixed voltage output of about 5V.

The discrepancy is due to the original calculation using a E6 20% Tolerance Resistor, only have E96 1% Resistors at hand.

The discrepancy is minor, and as most  Garden Railway activities do not require a degree in Rocket Science, can live with it!

In use on a Stripboard PCB, circuit and explanation is for another Blog Post..............