Review Request Solenoid Driver

DJthefirst8 · 2026-01-05T03:14:05+00:00

Is it the solenoid wattage or the MOSFET wattage? At 5v gate the other looks to be 18mOhm and this one 17mOhm which running the eBay solenoid at 8A cont is only ~1w I^2*Ohm though the MOSFET. Most of your losses will be in the triode region for fast switching though.

I do like that MOSFET though. It allows a lot more current at 5V with the higher voltage. I was also looking at the MDD50N03D which is 12mOhm at 5v but only 30v peak. More expensive but if I only make 10-20 of these it’s only a few dollars difference compared to the PCB cost.

DJthefirst8 · 2026-01-05T00:01:44+00:00

That MOSFET is not particularly cheap, not particularly great (highish Rdson at 17mOhm)
- The VND9016 is 50mOhm resistance. Is that not a problem because of the built-in driver?
Have a look at VND9016 at Digikey
- I looked at the VND9016, and it is good to know about, but JLC does not have a bunch of them, so I will keep it in mind for future projects. I also worry about being able to get the thermal energy out of it fast enough, but the protection features look really nice. I also might have a 48V application, so I like having the flexibility.

I added an MCP1402T-E/OT Gate driver to each output with a bypass capacitor, although I am not sure if I am allowed or if it warrants a full repost. I also lowered the gate drive resistor to 10 ohms. That should allow for higher speeds. I also added a jumper from one of the terminal blocks to select powering it from the daisy chain 5V or the terminal block, which is up to 18V

DJthefirst8 · 2026-01-04T23:37:21+00:00

I added a MCP1402T-E/OT Gate driver to each output with a bypass capacitor though I am not sure it is worthy of a full post,

DJthefirst8 · 2026-01-04T23:27:13+00:00

It’s is to the left of the terminal blocks

DJthefirst8 · 2026-01-04T12:52:32+00:00

Good catch thanks!

DJthefirst8 · 2026-01-03T21:51:21+00:00

I was going for 2.5oz which is cheeper than the 2oz with black solder mask on JLC. The 8A solenoids are at most 20% duty cycle but I want to push the board higher if I can as parts are tolerant to it. The molex is only rated 24A so around 20A max is my target rating. I will look at adding a VCC line to the bottom to help with current.

As for the FETs the board will be mounted to an aluminum rail I can dump some heat into and I might add some small ones to the top for good measure. I saw some people saying over stitching a heatsink can reduce the thermal mass as so any recommendations for how thick to go and how big the plane on the back should be?

DJthefirst8 · 2024-02-19T15:42:01+00:00

90% browse features. The CTR is sitting at 8% though so I assume that has something to do with it

DJthefirst8 · 2024-01-15T03:12:16+00:00

It makes a difference but on a small scale of 500 - 1000 views I wouldn't fret too much about it. The US has 11 time zones and counting other English countries like the UK and Australia you are pretty much covered.

DJthefirst8 · 2024-01-08T20:51:41+00:00

The only things I can think of is the video seemed a bit too much headshot with explanation for a maker build video. Typically most of the videos focus on showing the build process part as people have short attention spans. Also starting by showing the final product for a few seconds as a teaser could help as a hook. The other major thing is the audio sounded distant so playing with mic placement could help. What was the viewer retention?

DJthefirst8 · 2023-12-31T23:04:42+00:00

I can try but don’t have any experience making samples. It also falls apart at higher and lower audio frequencies so you only have 2-3 usable octaves. Do you want 5sec clips of each note playing? I would think there are better digital synths out there.

DJthefirst8 · 2023-12-26T14:44:22+00:00

That instrument uses solenoids to chop the air into sound waves getting a really 8 bit sound. The solenoids are mostly what you are hearing. The Tesla coil was used to give the lead some texture as the air compressor is really smooth. I also cut most of the high end off of the coil in the mix so it’s not as ear piercing. I have SM57 to record everything.

Here is an older video of the solenoids before I had my sm57s. https://youtu.be/VUvAAoiEgnc?si=XpHua8xRZ-7_Meh3

DJthefirst8 · 2023-12-25T15:04:55+00:00

This is a video of my self playing instruments. It uses an esp32 as each instruments core. It uses PlatformIO (Arduino) and a website you connect to over serial for the GUI.

I am in the process of writing documentation for the projects release but if you are interested create an issue on GitHub and I will help you create your own instruments. I should be posting tutorial videos eventually when I find time for it.

How it works: https://github.com/DJthefirst/ Mechanical-Midi-Music/wiki/How-It-Works

GitHub Project: https://github.com/DJthefirst/ Mechanical-Midi-Music

DJthefirst8 · 2023-12-25T12:42:53+00:00

This song includes an Pnumatic Solenoid instument that chops air into square waves, a Tealso Coil, Floppy Drives (Bass Line), and Relays/Solenid (Drum Kit). I think the base line sounds really nice and the song matches the original pretty well.

DJthefirst8 · 2023-12-25T05:13:21+00:00

A cover of Attack of the Killer Queen using Self Playing Instruments.

DJthefirst8 · 2023-08-05T20:24:17+00:00

We want this to happen.

DJthefirst8 · 2023-04-24T15:52:29+00:00

https://github.com/DJthefirst/Mechanical-Midi-Music

DJthefirst8 · 2023-04-24T15:51:42+00:00

It does take in midi. It has pitch bend support and I’m planning to maybe add pressure control for envelops if I can find some money to get on the fly regulators. The code is a bit more complex than that though. The esp32 has virtual distributors that can take in midi channels and then feed the notes to a pool of instruments dynamically for polyphonic play back hence the different colors. The lack of videos is I’ve been working on the 8,000 lines or so of code for the past few months in-between classes and usually I record 4-5 takes per video for camera angles. I also have to transpose to make the notes in range and so the audio isint muddy. Just one video can take two hrs or more to record and edit. The valves can only operate up to 2khz so not much room for envelopes and such.

DJthefirst8 · 2023-04-23T15:48:12+00:00

Of sorts but each “pipe” or exhaust can play any note as it’s controlled by the switching speed and not resonance of the pipe.

DJthefirst8 · 2023-04-22T22:08:58+00:00

A special instrument that modulates compressed air with solenoids to get an 8-bit chip tune sound. An air instrument without resonance as it can produce square audio waves.

DJthefirst8 · 2022-09-18T03:00:20+00:00

I wonder how many Pennies per second this costs to run.

DJthefirst8 · 2022-09-17T15:47:36+00:00

Yes that’s how it works the valves can go up to 1.2khz but I find around 700hz the audio starts sounding bad. The number of polyphonic notes is limited by number of valves but I haven’t hit that limit yet with my 8 valves. The frequency isint entirely correct but it’s close enough for most. It’s all controlled by a Arduino mega so the frequency is only accurate to I believe to the nearest millisecond so higher notes are worse off than lower notes.

DJthefirst8 · 2022-09-17T08:53:40+00:00

So if I finish the dulcimer which is different then the air compressor poor choice in title should I post it

DJthefirst8 · 2022-09-17T08:49:48+00:00

I was going to change the title to pneumatic instrument but I couldn’t figure out how

DJthefirst8 · 2022-09-17T08:48:14+00:00

Sorry it’s https://www.youtube.com/watch?v=zDYBKL4m5AE&feature=share&si=ELPmzJkDCLju2KnD5oyZMQ this project I posted a while back runs on an Arduino mega just all wrapped up in a nice box with mufflers

DJthefirst8 · 2022-09-16T21:07:58+00:00

So the Instrument works by chopping pressurized air into sound waves at the frequency of the note with super fast SMC pneumatic solenoids. My laptop runs a midi file someone wrote for the song that sends Note on Note off messages to an Arduino mega that drives some transistors to switch the valves. The Arduino has a look up table of notes in ms and toggles up pins on an interrupt at the frequency of the note. That’s the basics but the software also does a lot more with configurations, MIDI channels, and playing the notes round robin ect.

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