Hello everyone! I (potentially stupidly) decided to make the WHAMMY my very first electric project, and I'm a little stuck. I'm currently on step 12 of the build guide, and I'm only reading +/-2.3V, not the +/- 17 that I'm supposed to see.
I should note that when I do this with the top AC pin connected to L and the bottom AC pin connected to N, the LEDs don't light up, but if I change it to N and Gnd, respectively, the LEDs light up but I still only get +/-2.3V :/.
While I technically passed my intro to circuits class in college, that was 10+ years ago and I don't remember any of it, so I'm completely stumped. Does anyone have any ideas as to what I could be doing wrong?
I should note that when I do this with the top AC pin connected to L and the bottom AC pin connected to N, the LEDs don't light up, but if I change it to N and Gnd, respectively, the LEDs light up but I still only get +/-2.3V :/.
While I technically passed my intro to circuits class in college, that was 10+ years ago and I don't remember any of it, so I'm completely stumped. Does anyone have any ideas as to what I could be doing wrong?
Try measuring the voltage on C18 and C19 which are easy to get to as they connect to R20 and R21.
What voltage do you measure on each? Make sure your meter is on DC volts and not AC volts.
You should see at least plus 22 volts and minus 22 volts. If that is OK then move along toward the regulator. You should see the same voltage on all these points.
Hello! Thank you so much for the help!
I'm measuring 30.28V between C18+C19. All of them measure about the same (30.42V across C14/C15, and 30.49V across C18/C19).
It turns out that my previous post was incorrect - I think I was just seeing residual voltage when I'm connected to L & N - I get nothing when . The above photo and measurements were taken with me connected to N & G for the top & bottom connectors, respectively:
Once I let the residual voltage drop, I'll provide measurements using L + N (unless told otherwise
)
Thank you so much for the help!!
I'm measuring 30.28V between C18+C19. All of them measure about the same (30.42V across C14/C15, and 30.49V across C18/C19).
It turns out that my previous post was incorrect - I think I was just seeing residual voltage when I'm connected to L & N - I get nothing when . The above photo and measurements were taken with me connected to N & G for the top & bottom connectors, respectively:
Once I let the residual voltage drop, I'll provide measurements using L + N (unless told otherwise
)Thank you so much for the help!!
So you have to follow those voltages along to the regulator.
We also have to be clear on the measurements. Your black meter lead stays on ground at all times. That is the junction of C18/C19. All voltages are measured from here. Was your measured 30 volts across each cap (which would mean 60 volts in total) or were you measuring from one rail to the other?
If you had only 15 volts across each of those caps then that is insufficient but you still at this point need to make sure those voltages are still reaching C6 and C11 which are at the input to the regulators.
Aaah, I see what you're saying now. Sorry! When measured that way, I measure the following when using L & N for top & bottom AC connections (no lit LEDs), respectively:
C6: 1.269V, C11: 1.794V, C14: 1.794V, C15: 1.269V, C18: 1.793V, C19: 1.268V
Note: I forgot to capture +/- on these
When using N & Gnd for the top & bottom AC connections, respectively (lit LEDs) I get:
C6: 15.24V, C11: -15.27V, C14: -15.28V, C15: 15.32VV, C18: -15.29V, C19: 15.33V
If I switch the N & Gnd to be bottom and top AC connections, respectively (also lit LEDs) I get:
C6: 15.24V, C11: -15.19V, C14: -15.23V, C15: 15.25V, C18: -15.23V, C19: 15.25V
C6: 1.269V, C11: 1.794V, C14: 1.794V, C15: 1.269V, C18: 1.793V, C19: 1.268V
Note: I forgot to capture +/- on these
When using N & Gnd for the top & bottom AC connections, respectively (lit LEDs) I get:
C6: 15.24V, C11: -15.27V, C14: -15.28V, C15: 15.32VV, C18: -15.29V, C19: 15.33V
If I switch the N & Gnd to be bottom and top AC connections, respectively (also lit LEDs) I get:
C6: 15.24V, C11: -15.19V, C14: -15.23V, C15: 15.25V, C18: -15.23V, C19: 15.25V
This L and (live and neutral?) sounds scary......
The second half of the above post makes sense.
C18 and C19 each have 15 volts across them, the polarity will be correct or they would have popped by now and that voltage also appears across C6 and C11. There is no excess current being drawn as that would show in those two readings.
15 volts is not enough. Your transformer says 18 volts per winding and so you should be getting 18*1.414 which gives 25 volts DC. At low current loading it should be a bit higher still.
First thought. Is the primary (the two 115 windings) wired correctly. Assuming you are on 115 volts AC mains then if you have them wired in series it will be wired for 230 volt mains and the secondary voltage would now only be half the marked value. That would give the low voltages across the caps.
The second half of the above post makes sense.
C18 and C19 each have 15 volts across them, the polarity will be correct or they would have popped by now
and that voltage also appears across C6 and C11. There is no excess current being drawn as that would show in those two readings.15 volts is not enough. Your transformer says 18 volts per winding and so you should be getting 18*1.414 which gives 25 volts DC. At low current loading it should be a bit higher still.
First thought. Is the primary (the two 115 windings) wired correctly. Assuming you are on 115 volts AC mains then if you have them wired in series it will be wired for 230 volt mains and the secondary voltage would now only be half the marked value. That would give the low voltages across the caps.
Not easy to see on the picture but you have the LEDs, the regulators, and the capacitors C8 & C10 installed but I cannot see the 1K biasing resistors R10 and R14 for the LED. Did you install them, as they are needed for the regulator to work.
(I am just building my Whammy and have the board on my desk right now, though I am not as far as you)
(I am just building my Whammy and have the board on my desk right now, though I am not as far as you)
Good that I posted, because I soldered them in, though I did not power it up yet.
But then the schematics only talks about R9 and R13, and I am still scratching my head as to why you would use R10 and R14 when you configure the regulator without LED (15 Volts setup) but not when you are using the LEDs. After all, the bias current goes through the LEDs and keeps them in a stable region, as opposed to the LEDs just getting the current from the ground pin of the regulator
I'm running into an issue. I'm getting no power from the IEC inlet when plugged in. I've checked that the fuse is properly installed (I've even gotten new fuses on the off chance that both fuses I received were bad) and the power cord I'm using definitely works. My guess is the inlet itself is bad, but I wanted to ask here before ordering another one just in case I've overlooked something simple.