Equilux retaining power

[benny_profane]

I’m measuring power in the Equilux after power is cut (and the LED will stay lit for a bit). Have others noticed this? Not sure if a schematic is available for this one, but I suspect the inductors are storing then draining power.

 

[Cybercow]

Capacitors can store and slowly discharge voltage; while inductors will store and discharge magnetic energy. Considering there is likely a capacitor closely associated with the LED, that is from the where LED staying on a bit comes. The inductors used in the Equilux have nothing to do with the LED and are not responsible for keeping the LED lit for Any period of time after power is removed..

 

[benny_profane]

Yeah, that’s why I’m confused here. I’m measuring voltage potential at the DC jack after power is removed.

 

[Cybercow]

That will be the power filtering cap(s) slowly discharging.

 

[benny_profane]

That, of course, makes sense. However, the duration is curiously much longer here than other cases. The power block is quite standard as far as I can tell. I can’t tell why this build in particular is taking about ten seconds to fully discharge.

 

[Cybercow]

Without the schematic and a diagram of EVERYTHING connected, context is difficult to maintain in electronics.

 

[Bio77]

Maybe check your ground connections at your input jack. Or remove the ground connection to the output if you hooked up both ground wires. With an inductor there will be stored energy if there is current. Just spit-balling, but if there is a ground loop, seems like you could have an unintended current.

 

[music6000]

Full size or mini version?
Pictures Please?

 

[benny_profane]

Maybe check your ground connections at your input jack. Or remove the ground connection to the output if you hooked up both ground wires.

Ground connections are solid. I’ll try disconnecting the output to see if that does anything.

This is curious more than anything. The pedal is fully operational, but the discharge time is ~20 seconds with the LED in circuit.

I didn’t implement it here, but I often use a 10-22uF cap to ground with my LEDs to create a fade effect with the discharge (and mitigate current spikes). Those fades typically last about 1 second.

@music6000 it’s the full-sized version. Pictures pending.

 

[Bio77]

Do you have any 250V caps in there?

 

[benny_profane]

This one is sorted. I had been cutting power—but not removing the jack. I tried that, and the circuit power immediately fell. I used the same power supply with a different build. Same issue with the long LED fade after cutting power.

This is a wall wart I typically use just as a bench source and don’t typically use it with full builds. I powered the wall wart without a load and measured the potential. After cutting power, potential fell very slowly.

I’m thinking this is an issue with the power supply holding charge and discharging slowly through the low current load LED. Thanks all.

 

[Cybercow]

This one is sorted. I had been cutting power—but not removing the jack. I tried that, and the circuit power immediately fell. I used the same power supply with a different build. Same issue with the long LED fade after cutting power.

This is a wall wart I typically use just as a bench source and don’t typically use it with full builds. I powered the wall wart without a load and measured the potential. After cutting power, potential fell very slowly.

I’m thinking this is an issue with the power supply holding charge and discharging slowly through the low current load LED. Thanks all.

It's not really an "issue' with wall-warts, it's part of their design. The filter caps in them are usually in the 47µF to 330µF range and will bleed slowly after power has been removed from their input. So if still plugged into a pedal that is engaged when the power is removed from the wall-wart, the LED in the engaged pedal will slowly fade out while the wall-wart cap(s) bleed out. (Pretty much what you said.) Glad you sussed it.

 

[benny_profane]

I didn’t mean “issue” to be negative—just the phenomenon that was being discussed. Good points though.