Testing Traco DC/DC Converters 24v to 5v or 12v


#1

Happy Friday Particle People.
Thought I would share my nonprofessional test on two of the TRACO POWER DC/DC converters.

I first one I bought was the model TSR 1-2450 This unit will bring a DC voltage down from 24V to 5… well almost 5. When powering the Photon via the power shield, not using the terminal block because I am an idiot and bought the 5-volt unit not noticing the power shield accepts 7v to 20v, that is another story. Anyway, powering via the (Other 5 Volt Power Source Input, Next to the USB in) that accepts 5v I would maintain around 4.82 volts. When connecting the battery the voltage would drop to around 4.62 until charged then peak back up to around 4.75. This is all while running an 4-20ma sensor I2C shield and publishing every 60 sec. I added a temperature sensor to the board and the TSR 1-2450 peaked up to around 105 deg when under load.

Then I got a little smarter and ordered the TSR 2-24120 which will accept 15 to 36 VDC and output 12 VDC at 2.0 A max. I am hoping to use this on the Electron that is on order but am testing it with the above scenario. Since the voltage drop is much lower this unit is very efficient. ( I am guessing here) Anyway, this unit is maintaining 12.02 volts to the power shield. I removed the temperature sensor as the unit is not getting above room temperature under load. Even with the battery attached the unit is maintaining 12 volts and has not dropped below.

So in a nutshell that’s what I got. Hope it helps anyone looking to drop some DC voltage.

I bought these on Mouser

The TSR 1-2450 was $6.07:
https://www.mouser.com/ProductDetail/TRACO-Power/TSR-1-2450?qs=sGAEpiMZZMsF1ODjcwEocAoK4mUDQwXnrxACikdcjMo%3D

The TSR 2-24120 was $12.46 : https://www.mouser.com/ProductDetail/TRACO-Power/TSR-2-24120?qs=NtE2QagKf6T34HiGRDOLrw%3D%3D

If you have any questions please let me know.
Cheers,
Tom


#2

@gasgen An equivalent but cheaper switching DC DC converter is the Recom Power R-78E5.0-0.5. I started using LDOs but when I started getting interested in lowing the power used soon realised that they are horridly inefficient (50%) whereas these switched DC DC converters are >90%. It is worth you looking for the advice from Particle on conditioning the 5V supply - I can see you have electrolytic cap. The other thing with the switching DC:DC converter is that they can kick out EMC so a suppression circuit is recommended, inductor and capacitor.


#3

Thank you so much for taking the time to comment. I still have so much to learn. I did a quick search on suppression circuits. It looks a bit complicated so I am going to have to keep searching for some more elementary school descriptions and examples. It’s amazing that I have not fried anything yet. Lol.
I will look at the Recom Power units you suggested. They are way lower in price that’s for sure. If you have any other tips for me please shoot them over. I will take any information I can get to help better understand the correct way of doing things. Thank you again.

Cheers


#4

@GasGen -

I found your post when researching Traco AC/DC converters as I am always looking to improve my designs.

I can agree with @armor, the Recom units are much more cost efficient to use it seems. I have been using RECOM RAC05-05SK unit in higher voltage applications and so far, no problems. I am switching from 240V AC to 5V DC to power a Photon via the VIN pin. There are several reasons for the 240V which is unrelated to your post, but in short, the RECOM units work REALLY well.

I even made a rookie error swopping probes around when measuring Amps on the HV PCB which, needless to say, ended up in a disaster, but allas… both Particle Photon and RECOM units survived the ordeal. It obviously did a very good job at isolating the low voltage DC side of the circuit from the HV AC side.

Apologies for the ‘non-electrical-engineering terms’, still learning as I go along :slight_smile:

Hope this helps!!

Regards,