Your jaycar experience is spot on to mine.
By left leg I am referring to the source. If I am looking at the flat side then it is my left.
Correct, the remote control has a 12v battery.
I am very careful with soldering. I’ve never timed my duration but I’d say it would easily be under 5 seconds and I also wait in between soldering for cool down if I have been heating the components a lot.
Well I’m at a loss as to the cause of failure. What remains as a cause are;
defective stock,
electrostatic damage at Jaycar, or in your care,
overcurrent, though it seems very unlikely that the remote would pull more than 200mA through the contacts it isn’t impossible when a very short duration startup pulse is taken into account,
mechanical shock, if the leads are cut with wire cutters that aren’t flush type.
You can exclude the optional series gate resistor as a cause. It really only begins to be important if you are turning the MOSFET on and off more than a hundred times a second, and it is for protecting the Arduino output pin from overcurrent during the instant that the gate capacitance is forced to change voltage level.
thanks… I haven’t retested the faulty MOSFET again, but I am now doubting myself because:
With a 9V DC battery powering the Arduino:
With a 9V DC power adapter powering the Arduino:
Is there a reason why current wouldn’t flow from the source to the drain in the situation of the DC power adapter above? I did notice that when I turned off the powerpoint after several attempts the button on the remote control pressed once.
Yes, there’s likely to be a reason. The 9V DC power adapter isn’t providing stable DC, or the voltage is not what you expect. Don’t tell me the nominal voltages of the two supplies; measure them when they are connected and the Arduino is blinking. What’s the model of power adapter? What’s the model of Arduino? I’m not sure what your 4.5V circuit is; that sounds wrong if it is meant to be the output of the 5V regulator on the Arduino board.
No worries mate. I’ll do as you describe. I’m out at the moment, but I can answer one question off the bat. The 4.5v led circuit I refer to is a separate breadboard with an LED, a resistor, and one of those plastic holders for three AAA batteries.
hi quozi, sorry to disobey your questions but:
I found an old school (before 1999) adapter I have that came with the the first telephone (uniden) I ever had personally. It’s a 9v 350mA and it works a treat.
the adapter which didn’t work is the one that came packaged with the kit I bought off here. Funny too that the adapter the kit came with had the american style plug on it. Either way, let me know if your curiosity above still exists and I will happily do the tests.
My guess is that your problem is, in part, that you’re looking at the labels on batteries and power adapters and thinking that’s the voltage you will receive at the Arduino power input socket.
It’s not that simple. Use your oscilloscope to measure the voltage over time.
The voltage of a power adapter may vary with load. A typical “9V 350mA” adapter being run by an Arduino circuit pulling 50mA may have a voltage of around 12V.
Some adapters give unfiltered DC, consisting of a series of sine wave hill tops chained together one after the other.
The voltage varies in time, and varies with load. That’s what “power adapter” means.
The label on such an adapter tells you the minimum voltage at that typical current, or it may be the maximum current at which that minimum voltage will be provided.
Regulated adapters on the other hand have a label which tells you their regulated voltage, and the maximum current you may draw before the adapter may turn itself off.
Regulated adapters are usually physically smaller, but way more complex inside.
(My preference is for unregulated adapters where lightning resilience, power surge resilience, best safety isolation, survivability in high heat, or generally long life is important. Otherwise I use regulated adapters; which have to be replaced more often.)