Testing a Dual Channel Signal Generator (#71)

[@Venomator.]

Up to 832 as I watch this one Martyn, well done! PS: I am always late to the pardy, having only just started getting back into electronics and chasing knowledge, so thank you too... 👍🏻 😉 🐍

[@rotorque4254]

Subscribed right now. Great explanations and demonstration. Thanks for the help.

[@MartynDavies]

You're welcome

[@peterduxbury927]

Just bought the backlit version today (same as yours). Just a pity that there was no instructions for its' use. Your 13 minutes of teach-in has been most valuable to me. This was really cheap on Ebay, about USD 8. I am not certain if the output would directly power a small Tweeter at approx. 20kHz, so I am experimenting with this.....I have not powered-up mine, and was wondering how the LED Display shows 20kHZ? I don't have the luxury of an Oscilloscope! Thanks and greetings from Australia.

[@MartynDavies]

Thanks Peter. There is a small howto on the icstation website www.icstation.com/signal-generator-pulse-frequency-duty-cycle-adjustable-module-display-150khz-p-12477.html). I don't have my unit to hand right now, but it looks like 20kHz would read as 20.0

[@peterduxbury927]

@@MartynDavies Thanks for the info, I am 74 yrs, and have had a deep interest in self-taught electronics. But this piece of kit (the backlit version with four (4) small keypads) is completely new to me, and I just had to have one! I had an RS Stock No. 610 - 405, and this had a variable frequency from 1 kHz to 20 kHz. This RS Unit, drove a Tweeter directly from its output. It's over 50 years old, and now inefficient. Not sure if the neat version that I have just purchased - could drive a small Tweeter on its output directly? I am truly impressed by what this small circuit board can do! Finally, I must admit that I had no idea what the "Duty Cycle" was! I had always thought that a Car Starter Motor had a short duty cycle, but I could not understand why any Frequency Generator should have a duty cycle..............? Now (with all thanks to you and your YT production), I was so pleased to gain this knowledge! Yes, I think that you are right about the display. Possibly the first decimal point will not be visible, and then read as '20.0' as you said.

[@MartynDavies]

@@peterduxbury927 I imagine that it can drive a tweeter - 5V is quite a lot of voltage in audio terms. I think experiment with a capacitor inline, since you don't want to sink much DC current through a speaker.

[@peterduxbury927]

@@MartynDavies Thanks once again Martyn for your help and advice. I do agree that any speaker does not like DC voltage and current, and (years ago) I read about amplifiers and "clipping" which can destroy any speaker by DC! I did read somewhere that the output current of this device was quite low, and in the low mA range, but a capacitor in line sounds good. Before beginning this project, I need to buy a small plastic Project Box from our local Electronics Shop, which is similar to the old 'Tandy' Shops. In our country, these shops are called 'Jaycar', RS - or Farnell. A pity that this device does not have a small LED when the circuit is energised, but I will add one to the 12VDC input via a suitable resistor, when I hook it all up.

[@DavidWatts]

I didn't know there were any cheap modules with a serial interface, good to know even if that one is a little dodgy.

[@MartynDavies]

The LCD one is better. The serial interface works, and you can read back the parameters - you could control the frequency and measure externally from a Pi etc

[@Usedrummer]

What program do i need?

[@ManOleg38]

Channels did not sinchromized :(

[@MartynDavies]

No, they seem to be fairly independent

[@ivand8393]

They are (only when the freq. are multiples)

[@arya8431]

is that 5v output?

[@pdoandika6763]

can i request a two channel pwm arduino program?

[@MartynDavies]

I'll see what I can do

[@pdoandika6763]

@@MartynDavies can you help me make a program dual pwm with 180 degree phase shift for duty cycle ≥ 0.5 using arduino

[@arya8431]

thats great testing, can you share arduino code for serial testing?

[@MartynDavies]

The code I used is published on my github (github.com/magiccow/serial-to-freq-gen), but as I said in the video the serial port doesn't seem very reliable on this module. If you want to use serial control, I would recommend the single channel module I looked at before ( kzbin.info/www/bejne/g5yyYnuAbpaWh9U ).

[@kedarghatnekar4478]

@@MartynDavies hello, I am novice in electronics, I am looking to built a specific device providing 2 channel and micro ampere output and control the frequency of channel 1and 2 from computer. Also further the idea is to write frequency pairs with specific timing for each frequency and to save the program and then run the machines ( in short automated firing of frequencies of saved frequency pairs) My question is is it possible to do with above pmw generator. Thanks

[@MartynDavies]

@@kedarghatnekar4478 I could not find a way to control this module reliably from a computer, so you are probably better using something else. Arduinos have PWM output, and are computer controllable. Something like the Duemilanove has multiple outputs, or you could use two cheap clones (e.g. Pro Mini or Nano) to give you the two channels. If you search on Google for 'arduino pwm multi channel', you can probably find a design to base it on.

[@kedarghatnekar4478]

@@MartynDavies OK thanks, anything /any model you can suggest?

[@secrettreasure1388]

''''''' THANKS.,,,,,,,,,,!

[@rickneill6924]

If anyone is interested in the schematic for this generator it can be found here atm:- image.easyeda.com/histories/1a1fd5ef15c7433d8807ef1a19b9a67b.png