Pulse Width Modulation (PWM) Generator

[FioranoCars]

I'm looking for a PWM generator, either suggestions to build one, or something like these:

http://www.autodiagnosticsandpublishing ... ester.html

http://www.plusquip.com.au/products/tes ... or-tester/

Does anyone have one of these, who can comment on their quality?

Ideally would like to be able to bench test throttle bodies (butterfly types) as well as run cooling fans (ie Mercedes) and other units that use PWM control, both on and off the car.

Any thoughts of ideas welcome

Many thanks
Richard

[tech4cars]

Richard,

I purchased the autodiagnosticsandpublishing.com tester and find it quite useful. I am currently working on a project involving throttle body testing and find it quite useful. It appears reasonably well made, although I am planning to eliminate the pigtail cables and install banana sockets on the box directly as I have a large collection of connector adapters to banana sockets and lots of banana cables. They only provide alligator clips and two sizes of terminals with the device, which doesn't cover everything. For the price, I thought it was worth it.

Myles

[FioranoCars]

thanks for the post, sorry for the delay in answering!

I'm not in a hurry to make a decision but think it'll be a useful addition to the diagnostic arsenal, especially to help distinguish harness faults vs components, by being able to run the components/give ECU's a know signal.

I'm hopeful that others might share their experience, but seems like a niche tool that few would have unless they already had a scope, so hoped these forums might be a good place for some feedback ... so come on anyone out there care to share ... or on other tools or methods used?

thanks
Richard

[Robski]

https://youtu.be/SzjyVlv4jWQ

[FioranoCars]

thanks Robski
It looks like autodiagnosticsandpublishing have been busy with a new unit, and oddly it's cheaper but with wider control/settings. Their website link is here:

http://www.autodiagnosticsandpublishing ... river.html

Be good to hear of experiences of using these either in the workshop or on the bench, as none are UK or European, and autodiagnosticsandpublishing's you tube video's hardly give a great impression!

thanks
Richard

[Fat Freddy]

I think you would have far more fun building one. You could something far more versatile than that using a micro controller like a PIC. A few quid would give you a display screen to display V, Duty cycle, frequency, pulse width or what ever. Add an AD595 and you'd have that thermocouple idea happening.
You can add an Injector/coil driver, etc.. The list is endless.
.
Cheers
FF

[FioranoCars]

Thanks FF

That certainly sounds like a fun idea, sadly my knowledge of PIC is less than scant! Have you got some sites you can point me to that you recommend please, and specifically PWM projects?

I have found a AD595 project:
http://www.electronics-lab.com/project/ ... amplifier/

Ok, I have "finally" found some useful info, clearly searched using the wrong words! Doh!
http://www.circuitsgallery.com/2013/08/ ... ation.html

Programming is not an issue, well 20 years since any C - but I'll cope, however any really good novice guides to the world of PIC you can point me to?

Also, if you have time/know the answer, would the above PIC PWM example be able to directly drive a 20amp fan/60amp whatever, or would some other "upscaling" be needed to cope with the the load?

thanks
Richard

[Technician]

Also, if you have time/know the answer, would the above PIC PWM example be able to directly drive a 20amp fan/60amp whatever, or would some other "upscaling" be needed to cope with the the load?

thanks
Richard

Richard,

It's not the only tool you'll need, but invest in the Power Probe Hook and a lot of your problems are sorted.

[Fat Freddy]

That certainly sounds like a fun idea, sadly my knowledge of PIC is less than scant! Have you got some sites you can point me to that you recommend please, and specifically PWM projects?

Programming is not an issue, well 20 years since any C - but I'll cope, however any really good novice guides to the world of PIC you can point me to?

This is the programming tool I use. https://www.matrixtsl.com/flowcode/

You can not go wrong. Have a look on the forum. A lot of the self learning projects are directed at Automotive. The basic program is free. From then on you can purchase more advanced capabilities dependant on your needs including CAN capabilities.

As far as the AD595 goes. Just make sure you use quality components and a accurate voltage ref/reg. After that the datasheet tells you everything else you need to know. Add the PIC you can program and add a HD44780 (?) LCD from China and you're good to go.

As far as individual circuits go. I look for a circuit that may contains say a MOSFET that can deliver the current at the speed I need and work from there. But you will run into problems. Such as an coil driver circuit isn't isolated from the PIC well enough it can reboot the PIC. So if you are running a sequence of events it can get frustrating. But that's all down to circuit design.

Read the forum posts and I think you will have second thoughts about buying a PWM generator. It's not all plain sailing and does have it's hurdles but certainly do able.

HTH
FF

[Fat Freddy]

Just had a look at some of the components in Flowcode 6. It's got everything you need. It can even interact with certain series pico scopes 2000 (but probably be made to work with others), open and set channels etc. (Not entirely sure how it interacts ). Use a touch panel from 4D systems and you wouldn't even need a button.

Flowcode screen shot

HTH
FF