You can try checking whether the 54v supply has any voltage spikes if you haven’t already. 60-to-5 converter is most likely a switching converter and they draw high current instantaneously and can cause spikes if not filtered properly which may affect the functionality. This may not show up in DC voltage measurement, and daisy chained boards may still function if they are filtered well. One of the daisy-chained boards may be causing the disturbance too, and maybe top board is filtered well but bottom isn’t for some reason, maybe a soldering error(e.g. filter capscitor ground connection, poor soldering may be conductive but with high inductance, hindering filter functionality). So it is good to check supply quality. Also what do you mean by not powering up? Is 3.3v not working? What about 5v?
The point of the diode is to prevent reverse current that gets induced when a (brushed) motor is turned off. It essentially turns into a small generator while spinning down, and the diode essentially short circuits that. It prevents damage to the rest of the circuit. If that motor is brushless (with an integrated control board), you likely won’t need it but it doesn’t do any harm either.
With soldering you want to maximize heat transfer at all times so flat surfaces (chisel tip for example) are usually ideal. If you want to remove solder from a hole in a PCB you’re better off with a round tip as that has the most contact area then. It will make it easier to use a solder sucker in that case for example. Personally I have the chisel tip on 90% of the time and might be willing to switch to the large flat one.
maybe something like littlebits kit? I haven't tried them myself, but they look fun, educational and kids friendly (not sure about 3yo thou) https://www.youtube.com/watch?v=E7B0mWvnE1Q
That’s why they call it a decoupling capacitor, cuz you usually just need AC (signal) at the out of a circuit, you don’t need the DC part of the signal.
I think that it is the same stuff, just will propellant added in the aerosol. A small squeezy bottle with a needle is better if you have live stuff nearby - but you can always fill one from an aerosol
I’m old school. I’d reverse engineer that part of the board, work out what the resistor was doing and then choose a value, much as the original designer did.
From that small section of the board - I’d guess that it is a resistor in the CR voltage dropper, used to power the electronics.
You measured the resistor at 403 Ohms? That would qualify it as “not failed” then. Resistors pretty much exclusively fail open, or on rare occasions, out-of-tolerance on the high side. After 5 years of doing electronics diagnostics for USAF aircraft, I never say any other type of resistor failures.
I’ve updated the original post. In any case, the question still stands - would at least like to find more available options, and understand why the ASMedia ones aren’t available.
askelectronics
Top
This magazine is from a federated server and may be incomplete. Browse more on the original instance.