How to make a Direct Voltage Adapter (DVA) to test CDI ignition
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- čas přidán 25. 04. 2015
- In this video I make up a Direct Voltage (Peak Voltage) Adapter for testing CDI ignition systems. This is a simple circuit that is quick to put together and can save quite a bit of money over making a commercial one.
For a video on using this adapter see: • No spark? How to test ...
A Direct Voltage Adapter is used to measure the peak voltage coming out of a primary coil and a pulse or trigger coil. This is an important step when diagnosing a problem with an outboard as it can often he hard to tell the quality of the spark you are getting, or where the problem lies if you aren't getting any spark at all. I will be doing a complete follow up video on using this device soon.
The capacitor is a 22uF 400V, R1 is 300 ohms and R2 is 1M ohm.
!!! UPDATE !!! For testing ignition coils R1 needs to be by passed.
Here is the forum thread I used to source the design: forums.iboats.com/forum/engine...
Head over to Luc's CZcams channel if you'd like to see loads more electronic wizardry: / lucsmallau
I am having to check the peak AC voltage on the pulser output from the stator on my ATV. I bought an online adapter for $27 and it told me nothing concerning grounding. Thought I was going to have to use my back probes in the CDI, which I did not want to do. Your simple circuit showed me at a glance that the unit converted the AC to DC and you also said it would do it, so not worried anymore about taking a reading from the pulser to the chassis. You made this old woman very happy today. Spring is coming and I NEED that ATV to work!!!!
Fantastic!! I know it has been 8 years but the information is even more necessary in today's situation.
Thanks from Montana for taking the time to make your videos, very clear and informative.
Thanks mate!
Fantastic job! Very generous and helpful of you to share your knowledge. I know it will help me troubleshoot my ignition system issue!Thank you
Thanks Ron. You're very welcome. It's motivating to hear the videos help people. :)
Many thanks for sharing your knowlege ! It is very well explained and will be very helpful to find why my Yamaha outboard does not make sparks.
Thank you very much for the reply looking forward to learn more from you. Sincerely, Ricardo
320 VAC is the peak of the AC sign wave. 240 VAC in Aust and NZ is the RMS
Nobody mentions about this, but you have a great voice to listen too. This really helps a lot in understanding what you explain. Great video's, really enjoy them.
Thanks mate, I'm glad you are enjoying the vids and find them easy to listen too. I worry a lot about the audio, particularly in these early videos.
yeah I understand, a wireless lavalier microphone with a low frequency cut off and a windshield would help a lot ! As a cameraman I can say audio is more important then the image. If you're unable to hear / understand the item, it's worth nothing. In this video all you can do is apply some audio filters in post production. Especially filter out the low frequencies and wave sounds.
Have a nice day! ( BTW I have to replace my CDI on my Yamaha 8HP 4 stroke , It died on me just like that in a split of a second .I put it 1 hour in the oven with 100 degree celsius , but it didn't fix it haha )
Thank you for sharing your knowledge.
this is very helpful and informative thanks. . Another words this would be perfect to check signal for Rev counter on a outboard. Maybe do one of those videos test from the engine to the Tachometer. Thanks again
Sorry I missed your comment. That's a good idea, I might work that into a tacho install video one day.
Nice video! I dont know much about electronics... Do i have to pay close attention to how much voltage the resistor can handle when picking my components for this circuit?
Can you provide the peak voltage ranges acceptable for a Honda BF25 (25HP Outboard) for the Stater/exciter coil, Pulser Coil and CDI output to the primary ignition coils? I could not find them in the repair manual and it would be most helpful when using the DVA adapter I made from your instructions. Thank you for the DVA tool!
Great Video,
Helped me out a bunch...!!!
Thank you
Anthony casola You're welcome Anthony, glad it helped. :)
+Dangar Marine I been looking at the schematics on line they only show the 3 circuit versions. What I have a question about is the capacitor. Some show it as a 22uf 400v and others show it being a 2.2uf 400v. Can you tell me which is correct
I used a 22uF and it seems to work great. I do remember seeing a conversation about that on the forum thread I originally followed. A link to that thread is in the description.
Hi there Stu I’ve read a lot about this and built one only to have it blow it was not to the Same spec what components did you use?
Need to find what keeps frying Ecu on Tohatsu mfs30b. Cheers
Watched this video and as always I learned how to do some thing simply compared to what I was doing in the past. I no longer need to carry my CRO out to the garage to check for ignition pulses. What are the typical voltage you see using this adapter? As the circuit has only half wave rectification do you divide the expected voltage stated in the manuals by half as well?I made up a quick and dirty version just to see how went on the go kart - it worked well. One modification I did was to put Velcro on the back of the meter and on top of the box so I can stick the two together. That made finding space to sit the two much easier.
Hey Ron, good idea about using the Velcro to keep the two parts together. I imagine the figures in this video are pretty representative of most outboard CDI units. The values in the manual are true to the values shown on the meter, no need to adjust for the rectification. Was out last night but will check out your diagram tonight when I get home. :)
Great job Dangar I've already made one and it works perfect thanx for sharing that type of knowledge. Can you make a tutorial on oil gas self mix system? By the way that Heineken looks great.
+Ricardo Romero Hi Ricardo, glad your DVA is working well. Self mixing system is a good idea. There is always a lot of discussion about how they work and whether they should be disabled for safety and if so, how you do it.
Maybe I missed it bit I do not see or hear what the components you need are called of if certain ones are required. I can go I to a store and see a million different size capacitors and voltage regulators.
What are needed for this project
Nice video thanks. Going to TRY and make a dva, in the video you use a diode i need to find out what type if is cheers.
+TheDefenderdude In the description there is a link to the forum post where I got the circuit from, it talks about the diodes you can use there. I would cut and paste it here for you but it's an image unfortunately. Good luck! :)
Great info , my question is, if you have a mutimeter that has a cat , 600 volts range . do you still need the peek voltage adapter ?
Some high-end multimeters do have peak voltage features built in.
hi,,thanks for that ive got an engine that has no spark,coil packs ok and suspect stator or trigger ,switch box?
+Alan Blyth Yes, I would certainly look at the trigger and CDI output next.
Hey Stu, do you have a video of preforming a dva test on a running motor?
This video goes through doing some DVA tests. czcams.com/video/MDbvkFM1V_c/video.html
Hi, i can use for a TRX 450 2009 ATV , i need change something ? You can let me know
Very well done. Thanks
Thank you too!
Stu, plugged into the mains which is 240V RMS it should equal 240 / 0.707 = 339 Volts peak so measuring approx 320 volts shows the capacitor is leaking across the 1M resistor a little bit
Interesting. I'm trying to think back but from memory I took that resistor out of the circuit in the end. I should revisit this refresh my memory.
hi,so will this adaptor i take it you switch the multimeter to ac selector not dc?
+Alan Blyth No, this adapter has a diode in the circuit which prevents the electricity from flowing in both directions thereby turning an AC current into DC.
Thank you for the good video,
I have 1 question: Can a True-RMS digital multimeter do this too?
I have to buy a new multimeter anyways so if that works will spend the money on a good one.
Cheers
I believe so, yes.
I saw you reply 9 monts ago. Cheers
hallo mr...
Is the dva circuit can be used to measure the unit cdi outboard engine yamaha v6 200hp 2 stroke, thanks?
Yes, this DVA can be used to measure any AC current such as a charge coil or ignition coil on any brand.
oke,thanks mr....
Its 300 ohm capacitor uses how many watts...?
What voltage should i be getting
I built the DVA as per instructions but when I compared to an $30.00 ES640 dva adapter voltages are way off. Only way I could think of validating build.
stu, I don't see a video of you using dva on motor?
It's an old one, but here's the link czcams.com/video/MDbvkFM1V_c/video.html
Can you test this by plugging it in the wall outlet or do you blow up the capacitor then?
No, tested just fine and gave the correct reading for the wall outlet.
@@DangarMarine Thanks for the reply, what happens if i use a different type of diode?
@@DangarMarine Thanks for the reply Stu. So the dva is still not working properly i didn't have the right diode so i used a different type of diode. I couldn't find a resistor of 300 Ohm so i used two resistors of 150 Ohm and put them in series. Everytime when i plug it in the wall one of the resistors burns, what causes this to happen?
Searched for a DVA meter and stumbled across a time-warped version of Dangar Stu! Mind blown
Question Stu, what damage could occur if battery leads fall off the battery when the engine is running?
You're main problem would be if the positive fell off and touched the grounded hull of a metal boat causing a short from the regulator / rectifier. Are you getting any problems with yours?
is there any way to test if I am getting any voltage trough the cdi unit without peak voltage meter? and what kind of signal comes out of pickup coil?
You will need either a DVA or a full oscilloscope.
+Dangar Marine I just have a multimeter at the moment, I dont need exact reading just proof that some voltage gets trough the cdi unit can I connect multimeter directly onto the cdi or will that destroy it?
Thanks you very much
You are welcome
22 uF or 2.2 uF?
The plans I followed said 22uF but I see designs using both so I'm not sure which is best.
in the video i don't see how much capacitor rating because the light is too bright please
22mf 400v
When finished, we use it to measure. Can the two ends of the measuring rod be measured when the polarity is reversed?
Is this bike a cdi
My boat is fibreglass
czcams.com/video/_GqGK7JXQXI/video.html
I disconnected the battery to recharge at one point, reconnected, went to start and the battery was still dead, so I went and pull started via rope on the flywheel, one of the terminals was dodgy and due to the vibration of the starting etc, one of the leads fell off the battery right when the engine fired up, the engine continued to run fine, so I turned the engine off. Later I was informed that removing battery leads at any time the engine is running can destroy the CDI unit or other electrical components, it even says in the owners manual not to run the engine with leads disconnected. The engine to this day still runs fine. I have also heard that Japanese engines in particular use different wiring set ups for the charging circuitry and are not susceptible to this problem / scenario. Your thoughts?
Just write a simple schem on paper!
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