Boost regulator broken?

Robotics and electronics discussion Electronics
1

Hello,

I’ve been testing one of your “Adjustable Boost Regulator 2.5-9.5V” and I think it has broken…

I used a power supply as input with 3.3v and using a multimeter I saw that the output was 3.3v. I turned clockwise the potentiometer a bit and the output rised to about 4v, I turned it a bit more (I wanted to get 6v as output) but it suddenly go back to 3.3v.

Now doesn’t matter what how much I turn the potentiometer, output voltage is the same as input voltage…

Could anyone help me, please? Is it broken? Could it get broken only turning the potentiometer? :frowning:

Sorry for my bad English and thanks a lot.

2

Hello.

You can break the boost regulator through a combination of high input voltage and setting the output voltage lower, but your 3.3V input sounds pretty safe. It’s also possible that you accidentally shorted something out around the time you did the adjustment. Did the unit ever work? Can you think of anything else that might have happened around the time the unit failed?

- Jan

3

Hello Jan,

I connected 3.3v positive terminal to input pad, gnd to gnd pad and the multimeter to output pad.

I didn’t short anything, but I forgot to connect the 1K resistor between gnd and output.

It looks like it worked for some seconds because output rised from 3.3 to about 4v.

Could it have broken because input (3.3v) is higher than an “out of range” output (2.5v)?

Thanks

4

No, I don’t think the 3.3V is higher than the 2.5V by enough to cause the problem. That comes up more when people want to do something like boost 6V to 9V but have it set to 2.5V, and then the output is forced to more than double what the regulator is trying to make it.

- Jan

5

Then I don’t understand what happened… :frowning:

6

Yeah, it can be difficult to track down what happened in cases like this. If you want to give another unit a try, you can contact us directly with your order number, and we can at least get you a discount on a replacement.

- Jan

7

I am having the EXACT same problem. I had called in and asked and followed the directions to the letter. I used a breadboard and a single 1.2v nimh cell, ran a 1k1 resistor across the gnd and vout and then put the meter on gnd and vout.

I get 1.23 before I put in the resistor and 1.11 after and no matter what I do the voltage wont change.

I thought the unit was bad so I took out another and it was the same thing, no change when turning the pot at all.

To be more careful I took the tip off the small screwdriver and turned it with only 2 fingers to be sure to have a light touch.

Any way to get a picture or video of exactly how to do this?

Thanks

8

Hi.

Your input voltage is probably too low (the minimum on the web page says 1.5V).

By the way, calling it the “EXACT” same problem might be overstating it. You, like puck2099, are reporting behavior consistent with a regulator that is not functioning (boost regulators have a diode from input to output, so you’ll always get the input voltage minus a diode drop if nothing else is happening). It is possible your regulators are broken, but even then, it could be for different reasons.

We don’t have any pictures or videos of this, but it really should be straightforward. I hope that when you apply a little higher voltage, both of your units will just work.

- Jan