99yam ?

[boscoe99]

I have been wanting an oscilloscope. Should have bought one years ago.

[99yam40]

Just ordered a peak reading adapter. Will see what I can see.

I would need to go find the info on making an adapter to show how the diode and resister are in the circuit, but being it has a diode, I would think it only lets one side of the wave in to charge the cap.
how can a cap build up more than the peak of the wave?

[boscoe99]

I would need to go find the info on making an adapter to show how the diode and resister are in the circuit, but being it has a diode, I would think it only lets one side of the wave in to charge the cap.
how can a cap build up more than the peak of the wave?

If the voltage from the coil is provided directly to the capacitor I don't think that it can.

Got this from the innerweb however. Don't think any Yamaha CDI uses a transformer. But...
Typical CDI module[edit]

A typical CDI module consists of a small transformer, a charging circuit, a triggering circuit and a main capacitor. First, the system voltage is raised up to 250 to 600 volts by a power supply inside the CDI module. Then, the electric current flows to the charging circuit and charges the capacitor.

[99yam40]

seems like I remember some strange things happening in the large rectifier system in the plants I use to work in.
Maybe some spiking happening that caused large voltage spikes in the 125 VDC control wiring.

I will have to think on this some more to see if I can get some of those memory cell to pop back up.

maybe it was opening and closing of some contacts in the control system caused back EMF spikes that kicked up the voltage very high that caused the failure of some components

[zenoahphobic]

In the old tube TV’s the high tension for the CRT was achieved by chains of diodes and capacitors that multiplied voltage with every diode/capacitor.
Go Google

[zenoahphobic]

Google “voltage multiplying”. I meant to clarify, that you certainly can increase dc voltage and maybe the adaptor is doing this in some way. Hard to know what circuitry is used in a meter and so adding components can produce seemingly strange results.

[99yam40]

here is a diagram

[boscoe99]

I will have my adapter today courtesy of Amazon. Will then test it on the output of my generator gizmo to which I can vary the frequency and the voltage by switching pulleys around.

Easier for me to buy the component than it is to get the piece parts. I miss Radio Shack.

[99yam40]

the cap was the hard one to find for me
I ended up getting some .47 MFD 600v caps.

I paralleled 4 or 5, but ended up just using one in the end and it seems to work OK
I agree without a local Radio Shack things are a lot more difficult

[99yam40]

I will have my adapter today courtesy of Amazon. Will then test it on the output of my generator gizmo to which I can vary the frequency and the voltage by switching pulleys around.

Easier for me to buy the component than it is to get the piece parts. I miss Radio Shack.

well did it come in?
and did you do anything with it yet?

we have almost a hurricane coming thru right now.
well maybe just a TS
just waiting for my elect to go out any minute

[99yam40]

well did it come in?
and did you do anything with it yet?

we have almost a hurricane coming thru right now.
well maybe just a TS
just waiting for my elect to go out any minute

Edit:
well it did go out a few minutes after I posted that 10:20 PM last night
just went to bed and tied to sleep some.
got up a 6:30 and fired up the generator
got frig and freezer running, a few lights, and computer/modem so I have phone and internet.
house is 77 degrees so not too bad for no AC all night
I see Center Point is reporting over 400K customers are out of power from the storm

[boscoe99]

Testing delayed til later today.

Brother lives in Willis. Has a generator. Not sure if he needed it or not.

Poor Louisiana. Too much rain.

[boscoe99]

Test results indicate that calculated values don't correlate with measured values. Why?

Not far off but... Is it close enough?

[boscoe99]

Yam can you measure the voltage from a wall socket with your voltmeter and peak adapter and tell me what you see?

Thanks.

[99yam40]

Yam can you measure the voltage from a wall socket with your voltmeter and peak adapter and tell me what you see?

Thanks.

from post #5
121.2 VAC

162.7VDC with adapter