unisolder 5.2c power supply

[TheBay]

I think you are overthinking this, nothing wrong with an EI transformer in your application.

[mastershake]

i guess they cause instability or something over there at the forum they are now suggesting not to use them. ill hook one up and see but sparky said you have to use the newest firmware to even get them to work right at all. didnt make sense when my brother in law told me sparky said that they wouldnt work over there. ill try one this weekend and see what happens.

[mastershake]

http://dangerousprototypes.com/forum/index.php?topic=7218.msg74079#msg74079

Here they are.

This is toroidal, JBC C105, 1/8 power:
X

There is no peaks, except really narrow negative one when the power is switched on. This is how it should be.

This is EI, on the same iron, 1/4 power (the leakage inductance is so large that it cannot power it with 1/8 power eny more):
X

Notice the HUGE negative peak when the power is switched on, and the HUGE positive peak when the power is switched off later. The second peak also adds some error to the measurement of the temperature, although this is eliminated in firmware with wave shaping.

So, again, USE TOROIDAL TRANSFORMERS with this project, please. You will save both me and yourselves much trouble.

Yes, the EI I am using for tests is REALLY NASTY one (in fact the original one from BK3000LF station), yours may look considerably better, but there is no EI transformer that can be even close to the HUGELY less toroidal transformer leakage inductance.

Sorry guys, but I cannot fight phisics. No one can.

P.S: The leakage inductance, measured:
- Toroidal: 3.76mH
- EI: 122.7mH (yes, one hundred and twenty two, point 7)

This is 33 times difference.

I may put a setting in the menu for not using partial power in the future if someone absolutely insists, but I still won't be able to guarantee that it will work with any EI transformer in the world.

[sparkybg]

Just use toroidal and you won't have problem. It does not matter how big - u can use 500W if you want - it just won't do enything more than 140-150W. The controller limits the RMS (not peak) current to 6A.

Yes, when non-toroidal transformer is used, there were problems when 1/8 power is used. This is now corrected, but anyway I STRONGLY recommend using a toroidal transformer.

The difference HUGE, due to HUGE difference in leakage inductance (33 times in my case).