Pilot
22.05.2021 12:55:55
R1 - is just a small resistor. here
See full version: Electrical; How to build Peak Voltage Adapter for any Multimeter
R1 - is just a small resistor. here
C1 - is just a Capacitor to store the volts so you can read them more
I have been having some electrical problems with my CR 250, as you guys know the manual says you need a peak voltage adapter. They are pretty expensive to buy so I made one and wanted to share with you guys how to build it. Everything including the box and test leads cost me about $9.00 at the electronics store. So here are the schematics.
D1 - is a Diode and the line after the triangle shows which way to mount it, there is a line on the actual Diode itself. (this only lets electricity pass through one way. more
Anyways here are some pictures of the one I made. It works great (unfortunately my bike doesn't !!)
The white X is a mess up that I didn't take out so don't pay attention to that.
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Used to test ignition and charging systems. Description per CDI Electronics: [links]
Troubleshooting Capacitive Discharge ignition systems commonly used on outboards often requires measurement of peak voltages. here
An AC voltmeter reads what is known as the rms ( root mean square) value. For a sinusoidal wave form that is 0.7 x voltage of the peaks of the wave ( 1/√2 x, to be more precise)
I hope no more than 15% of the final grade will involve DVA in's, out's, and why for's [links]
What importance does this device have for the use of outboards. What part of the outboard does this test. more
D1 is the diode. When soldering take care not to heat the diode by holding the wires with pliers and soldering quickly.
C1 is the 2.2 μF capacitor
R1 is the 1 MΩ resistor
I attribute this to the voltage drop across the diode, BUT wanted to voice this to the community to see if this is normal. here
Alternative design-very sturdy:
[links]
Don't see a voltage rating and it isn't 1/4 W more
Re: how to make a DVA adapter for multimeter more
This thread just doesn't die, LOL. To confirm Bill Rogers design, I tested out mine last night on a Merc stator, pulled over 400 Volts on the meter set to DC, I was impressed.
The only question left was what size C for a reasonable charge time and what sized bleeder for a reasonable discharge time without affecting the peak stored value. You (or bktheking) solved that problem for me.
Upon investigating, I found that you can buy an adapter for $25 from D3 Instruments, P/N ESI-640 for $25. [(941) 538-7775] or the whole meter with adapter on this site for $101 with free shipping (current special). One thing the meter has is a special DVA scale. here
So that brings up yet another question and that is what is the difference between this scale and the DCV scale as once you rectify and store pulses, you have a capacitor charged to a rather high (could be as high as 400V per my serv manual) DC voltage. so the 600DCV capacitor rating F-R mentioned is definitely necessary.
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Once I realized that you were trying to measure trigger pulses of maybe 1 micro second duration with a dead time of 1 milli second (at 1000 rpm) it seemed that rectification and storage was the only way to accomplish this. and you needed something (the resistor) to keep the charge on the cap from rising to the peak and just sitting there. had to keep it bled off. [links]
Funny this popped up today. Several days ago I was looking for this adapter so my thanks F_R for your comprehensive input. more
I became interested in this device as my Merc manual lists CDI tests requiring a DVA/DVM and lists a Merc part number (91-99750 which has been upgraded since the manual was published to the current number 91-99750A1). The one listed is a ESI brand. I got curious as to what it was, before I thought about what it was used for, and started investigating. more
Not mentioned in your fine piece of work F_R, (or I missed it) is what scale on your multimeter you use. Since it is DCV that's what it will be and the voltage range will be 1000. I just wonder why ESI thought it necessary to add a DVA scale? Possibly to up their profits by selling a fully functional multimeter with the adapter and quadrupling their bucks on the sale. Who knows.
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One final note. I personally would up the Diode's PIV rating to 1kv as my Merc serv manual is expecting to have a reading as high as 400v and I don't want a diode rated right at the max voltage I am anticipating. You can still use a low current device. As I recall, you can get a 1kv diode in that 4000 series of diodes that bk specified. I forget the number; been retired 6 years now but it's at the high end of the series.