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You can certainly use Arduino to pulse it very very quickly and have some fun figuring out how fast you can make the solenoid go. BUT... I doubt you'll get even close to ultrasonic. I looked it up and ultrasonic is considered above 20khz so let's assume you want to hit 20khz. That means that the solenoid plunger has to plunge and retract 20,000 times per second. That means each cycle of plunging and retracting has to happen in just 0.000050 seconds. That plunger needs to MOVE, and it can't move very far. It would be interesting to see how fast you could get it moving if you start playing with the variables: I would try a very strong spring, and block the plunger from moving out all the way (maybe like 10% of the normal travel distance). That way it's always mostly inside the coil (much faster acceleration), and also doesn't have to travel very far.

@@MattInglot Wow ! Hey thanks again for the in-depth explanation. 😨😊👍👏

You can use PWM to change the strength of the magnet which would in turn affect the velocity of the plunger, and maybe more importantly, how much force it hits things with (in the case of an application like a pinball machine flipper). Don't expect any fine control over this though! If you want that, you should really be looking at a stepper motor instead. Solenoids are great when you need that little bit of very sudden (and strong) movement. But you frequently see people trying to use them in places where a stepper is the better solution (and vice versa). Why controlling velocity of a solenoid is a funny thing: The acceleration changes with how much of the plunger is within the magnetic coil vs outside of it, because then more of the plunger has a magnet acting on it, and you get exponentially more force. Acceleration determines the change in velocity. So if the acceleration gets faster and faster as more of the plunger enter the magnetic coil, the velocity also gets faster and faster as the plunger enter. Put in simpler terms, when the solenoid activates, the plunger is initially moving very slowly (relatively speaking) and by the time it plunges all the way, it's moving extremely fast. It's not a linear speed. You can see force charts for some solenoids in their datasheet. Don't think you can see acceleration or velocity normally, but it's going to be a similar idea. All the action happens towards the end of the plunge.

An LED is a diode, but it's not a diode that has the right specifications to make it an effective fly back diode. For example, most LEDs have a pretty low reverse voltage (let's say 5v). Since the flyback diode is wired in reverse, it means that reverse voltage is very important because let's say it's a 12V solenoid, you've gone far past the reverse voltage and blown up your LED. Always easier to learn by doing though and LEDs are cheap, so experiment with it, blow up a few, and see what happens!

Yep. Mosfet could fail as well and cause the same issue. Something that does happen on pinball machines.

Yes FQP30N06L has a gate threshold voltage of 2.5v so you can power it with 3.3V. All of these parts have datasheets, so that's where you can get this info. Let's pretend you didn't have a part number from me that already works for your purpose though... you can find parts that meet your characteristics using the Digikey or Mouser search features. For example if you go into mosfets you can specify all sorts of characteristics to filter down to what you need (tip: you also want to filter by in-stock, and then usually sort by price). It looks intimidating at first but if you really put in what you want, you can narrow things down to much fewer options really quickly. ChatGPT can also be helpful for part numbers, but never trust anything it says without verifying against datasheets.

The diode polarity should be opposite that of the solenoid, else you basically create a short (sorry I THINK that's what you are asking). As for the fuse, take a look at the schematic posted in the description. When the fuse pops, does it create an open circuit?

Thank you!

I didn't. I am going to hopefully resume a pinball machine build, but I came to the realization that: 1) Full scale pinball machines are a lot more fun to me 2) Reinventing all the mechanisms from scratch is a LOT of fun and a great way to learn how it all works (and I'm glad I did that stuff), but it's not a great way to build a pinball machine. If you did want to go this route, it kind of sounds like you already know what to do. If you're going for a fully software solution, you would have an input on a microchip that indicates EOS is closed (so hookup the EOS to a pin on your arduino or whatever you are using). Then apply PWM to whatever pin controls your flipper solenoid so you can hold the flipper up but not burn out the coil. This is all assuming you're doing this for fun. if you are building a commercial mech then you should look into how the real mechs work... and understand that even some of the pin manufacturers have struggled to make really good feeling flipper mechs. There's a lot to it.

Unfortunately I'm not sure, you could try Googling or asking GPT. The first thing you want to consider with intermittent AVR errors is a loose connection or something not wired correctly.

You can use PWM to decrease *power*. That will technically cause the movement to be slower, but probably not in the way you are hoping. They give you movement that for all practical purposes is near instant, and that movement is not linear because as more of the plunger enters the coil, it accelerates due to more magnetic force being able to act on it.

@@MattInglot thx, menawhile I google and they are some ways, non linear - i do no think it is that big problem, it will be some neat function I think like exponetial or so would be imho possible to do a few test and approxime timing based on expected curve

Hehe yep! Huge plans for new attractions next year now that we have the extra tent space! :D

When I do a diode test, each Led lights up but are all still weak. When I did a diode test with the power On, the other Leds light more brightly when I do the test on one particular Led. I’m thinking this may be because I’m bypassing a bad diode with the probes? Anyone?

@@p.granger8824 I actually dealt with this in another light this year. One bad LED can absolute make the others go dim as it turns out. To test which one you can just power the LEDs individually. The diode tester on your multimeter only delivers enough current to barely light them up, but if you have a benchtop power supply you can set the current limit to something reasonable like 20ma, and then power each LED individually to find the culprit. That's how I found mine. If you don't have a current limiting power supply then a battery and resistor can accomplish the same.

Thanks. Now I just need to find some SM Leds. The ones on this light look smaller than the ones in the video, they are also square with no dome. Maybe I can just retro in another type if they fit under the lenses.@@MattInglot

Solenoids are great for short bursts of motion or force. Something like continuous vibration can be done of course, but feels like barking up the wrong tree. At minimum you will need a much stronger solenoid as you've found out. A big problem is that you can get much better performance out of a solenoid if it doesn't need to be continuously operating. You experienced this with your 12V to 6V solenoid experiment. If you had an application where that solenoid had to impart a lot of power but fire infrequently, using it this way would be totally legit.

@@MattInglot probably I'll just use a motor attached to the center with off balance weight to make vibration. It seems to be more efficient.

This punball is using smaller balls, 3/4 of an inch, rather than the standard of 1 and 1/8 (i thinl thats correct. Standard troughs, flippers and other mechanisms will not work here.

I wouldn't suggest it since putting blue leds into a white light will give you a blue light, so you're back where you started (if I understand what you are saying correctly).

As an experiment to see if you can catch it lighting up when power is stopped? Sure, give it a try and let us know what happens. As a practical thing? It's not something you'd want to do. Regular diodes are cheaper and actually meant for this purpose. Stuff that could be a problem with using LEDs: - LEDs have very low current limits. You could burn it out either immediately or over time. - LEDs have fairly low reverse voltage, so that could be a problem very quickly, and if you hit that threshold then you'll probably burn out the LED instantenously. - You mention a 12V LED, so that implies several LEDs in series to get 12V. I have NO idea how that affects the scenario and would love to find out. Alas I think it means nothing good :D Give it a try and let us know!

NO( normally open

​@@bananasplit4037 You should be able to find tutorials very easily on how to detect switch presses on Arduino, along with sample code. Then all you need is logic in your code that checks if the switch is pressed, then triggers the solenoid.

I have an attiny84 chip. can you tell me what happens if I don't install the bootloader. Is the code not going to work?

@@fil9625 Without the bootloader, you need to use a working arduino with ISP software to load a program directly. This is the same hookup that is needed to install a bootloader.

@@luhanxmonat I am going to use an Attiny13 chip. But it has only 1KB of flash memory. Can you tell me how much space does the bootloader take?

@@fil9625 The bootloader is about 0.5 k. I never use those because the attiny85 cost is just a bit more.

Super glad to hear thank you! Did you run into any setup issues or differences that I should note in the description?

@@MattInglot Your explanation was good, and my 1st attempt was successful, however things vent south after that! I could not reload the same chip with updated code! Have not tried a new chip yet. Have you encountered a similar problem?

@@xzadeh Sorry to hear. Honestly it could be so many things. I would suggest triple checking your connections and orientation of your chip because a wire coming loose on a breadboard or you putting the chip in one hole off or the wrong way is all stuff that's super common and has happened to me. Less common but possible is you bricked the chip. Usually happens if you mess around with the fuse settings, such as telling it to use external clock or setting the clockspeed too low.

@@MattInglot Hi Matt, now that I have had some time to check my setup, I don’t see any issues with wiring! Just a little background, I have been using Atmel Dragon to program ATTinys for years until my Dragon died and Atmel (Microchip now) no longer supports Dragon, they call it obsolete! Trying alternatives led me to Arduino. I don’t think it is a reliable alternative! Still looking for a programmer that I can reliably use without spending $100s dollars for a hobby programmer. Any suggestions? Thanks in advance.

@@xzadeh sorry but unfortunately "Arduino" is the answer. For what it's worth, I program ATTiny chips all the time and anytime I've had an issue, it's always been my fault in the end (wiring, pins, bricking the chip, etc).

Nicely done!