Motor Hat blinking power light Moderators: adafruit_support_bill, adafruit

[jebuk201]

Hi, I have had the adafruit motor top hat for about a little over a month, and everything seemed to be working until today. The green power light flashes once a second, and the chip in front of the green light (also the two capacitors) get warm. I'm presuming this is a power failure or overload of power. I just want to make sure and hope to figure out a solution to fix it, thanks.

[adafruit_support_bill]

What motors and power supplies are you using with the HAT?

[jebuk201]

I am using a power supply with a input of 100-240V 50/60Hz 1.6A and a output of 12V 2.0A. The motors I was using were knex motors, for a project I am doing. The knex motors seem to be typical 3v motor. This was all working, but I was using these motors a lot because of testing with my project.

[adafruit_support_bill]

Which K'nex motors and how many of them do you have connected?

Powering a 3v motor with a 12v supply will make it pull 4 times as much current and greatly shorten the motor life. With multiple seriously over-volted motors, it is possible that you are overloading your power supply. A blinking power LED on the shield is typically a sign of a power-supply overload.

[jebuk201]

The type of motor is shown below. I usually run 1 to 3 motors at a time, mainly because I'm still testing my project.

[jebuk201]

m.jpg (141.25 KiB) Viewed 552 times

[adafruit_support_bill]

Not sure which model that is, or what the electrical specs are. But it looks like probably a 130-size motor driving it. These generally draw about 250-300mA at the rated voltage. Since you are over-volting them by 4x, that will translate to about 1A-1.2A per motor. Just 2 motors would be pushing the limits of your power supply.

Also note that you will burn out these motors fairly quickly running them at that voltage. You can probably get away with 5v-6v. But 12v is really pushing it.

[jebuk201]

I would also like to point out that now when I plug in the adafruit motor top hat into the electrical outlet, the green light starts flashing right away with no motors running. Does this mean the circuit board is broken or is there a solution to this?

[adafruit_support_bill]

Try to isolate the problem. It could be a burnt-out motor with shorted windings. Disconnect all of the motors and see if the flashing persists.
It could also be a burnt out power supply. Try connecting a different supply.

[jebuk201]

Yea it has nothing to do with the motors. I powered it up with no motors attached. I also tried another power supply with an output of 10v, and the blinking still persisted, which the only difference was that the brightness of the green light was lower because of the less volts from the power supply.

[adafruit_support_bill]

Most likely it is the MOSFET on the HAT that is failing then. When did you purchase the board?

[jebuk201]

A little under 2 months ago.

[adafruit_support_bill]

Our replacement warranty on these is 30 days. But if you contact support@adafruit.com with a link to this thread, we can offer you a discount on a replacement HAT.

[jebuk201]

Thanks