Which Mastech 30V Power Supply to Get?

[LuxLuthor]

I know we were talking about these before, and I want to get one of these to be able to slowly ramp up the voltage &/or amps to see where various bulbs flash. I don't think I would need more than a 30V/20A supply, but I'm not sure what the difference is between the HY3020E and the HY3020D models.

Anyone understand the differences?

 

[SilverFox]

Hello LuxLuthor, (Oops....

It's simple, the switching power supply weighs 20 pounds whereas the linear one weighs 39 pounds...

Tom

 

[LuxLuthor]

Yeah, but what is making the heavier one heavier (& more expensive)....the "linear" vs. "switching" must be a clue. I don't see anything in the specs that explains it. I'm trying to figure out if the heavier linear one is better technically.

PS) Not sure who "Hello Lilith" is. LOL!

 

[SilverFox]

Hello LuxLuthor,

I also am not sure who Lilith is... Sorry about that.

This paper may help you understand the differences between the two.

Tom

 

[LuxLuthor]

Tom, thanks as always for your generous feedback.

LOL...unusual name too. I honestly can say I have never heard of anyone named Lilith. Yikes! Check out this Lilith Link.

I think the last page and table of your link does support the heavier linear being substantially better....however the stats displayed between the two models do not show any differences. Wonder if it is a web page/write up error.

Also, for some reason I missed this linked page which also addresses it pretty well. I guess I'll go with the switching E model, but now will call them on Monday to ask.

 

[SiMaster2003]

I believe the linear setup has less "noise" when you are using say a radio transmitter or amplifier, whereas the switching setup is more noisy, but cheaper and lighter. Maybe someone can clarify a little better than I can, but that's what I understand.

 

[LuxLuthor]

Tom, very useful that I called the owner of this webstore and gave him some of the battery charging, and light bulb testing examples when asking about differences between lighter E switching, and heavier D linear models.

As soon as I mentioned ANY battery charging, he was absolutely adamant that I should ONLY be using the heavier Linear model.

He basically said what has happened to the PS industry is people want a lighter, cheaper PS, which gives up the beefy transformer and heatsink, and higher quality steady power output. We had a 20 min conversation, so there was much more involved in the limitations of the "E" switching, but after the call, I ordered the more expensive D model.

 

[SilverFox]

Hello LuxLuthor,

Very interesting...

I have a switching unit and have not run into any issues so far, but I am all ears to learn why he suggests the linear unit.

I wonder if he understands that pulse charging is preferred to constant current charging...

Tom

 

[jimjones3630]

Both picked up on ebay are heavier Linears. can use to power short wave and the motorola R-101B is VC, CC, 0-20v, 0-40v, 0-5A, 0-20A, 0-40A make orginally for radios, is great as a battery charger and can power up short waves.

I'm prasing the R-101B because is such a great buy on used market, is out of production now but was made with many generic(non OEM) parts for easy repair.

 

[LuxLuthor]

Hello LuxLuthor,

Very interesting...

I have a switching unit and have not run into any issues so far, but I am all ears to learn why he suggests the linear unit.

I wonder if he understands that pulse charging is preferred to constant current charging...

Tom

Tom, I have been reading up on differences between Linear and Switching PS, and as you can imagine it is not an easy or simple topic. First is to see all the different types of SMPS topologies.

Next is to realize that the 50 kHz to 5 MHz switching rates of SMPS does not correlate to the pulse rates of "battery pulse" charging
(which allows time for replenished electrolytes to migrate away from electrodes) as an explanation of using a SMPS for this battery charging application. The variations in voltage, current limiting, pulsing, termination are all controlled by the hardware and algorhythms of a battery charger...and correlated to the chemistry type.

I'm not even sure I have any intention to use this Mastech for any battery charging purposes, since I now have two Hyperion 1210i's and Pyramid 10 & 20A constant power supplies.

All power supplies used to be linear. It is only the more recent electronics developments to make them cheaper and lighter that has led to the SMPS industry. They are not as "hearty/beefy" under load, nor as efficient.

Now whether a SMPS could suffice in our area of applications, and hold up long term, and with larger voltage and mAh battery packs, and with faster C battery charging (Emoli/A123), I am still reading.