DC-DC Adjustable Step Up Converter Output Problem

Any of the following:

• It was not fit for purpose at despatch
• It was not fit for purpose on arrival
• It was not fit for purpose after initial energising
• There is a short circuit downstream of it
• There is an open circuit inside it
• There is some other fault inside it
• It is connected into a load that is too big for it.
• Etc.

Thanks for the reply.

There isn't any load, it's connected only to the voltmeter.

The two 100v 470uF capacitors are in parallel and connected to the output, and the voltage measured is 0.60V, at the the other one 63V 1000uF I measure 12.02V (as the power supply output). What other component should I test to figure out the problem? have you some advices for me?

It may need a load to function properly.

I'd keep going if I were you.

That could be the problem, some types of equipment require a small load to allow them to "switch on". Try placing a 100 Ohm resistor of say 10 watts across the output. (TV repairs resistor)

If that does not help, it would appear that your unit is defective, so do the following:-

Do not give any ebay feedback at this point in time.

Write to seller and tell him it is defective, you want to send it back for replacement/refund. This is usually costly for you to return it.....

See how he reacts, Chinese suppliers usually simply cut of any further contact....eg. you are on your own.

Then write a factual feed back with no swearing, just the plain facts....otherwise ebay will simply remove it....

Or send old one back and wait months for delivery of a new one....

Best tip is to find a local supplier and not buy directly from China, or simply accept the risks involved.

Let us know how you get on....

Is the internal oscillator running at the stated frequency?

Is this a fly-back or a standard boost circuit topology?

Does the current and voltage curve traces indicate if the core is saturating or not?

Do all transistors and diodes turn ON and OFF properly?

Is the feedback network working properly?

Is the fuse intact?

Does ebay offer a warranty on this product?

How's the weather where you are?

yeah, plug it into a toaster oven, and see if that works. (ROFL) It does need the fuse checked, and you do need to at least minimally load the power supply for a test.

A weak fuse could be the problem (I suppose arbitrarily) if the fuse presents more resistance (by a factor of about 10) than the test load.