EPR Build Log

[velocity3x]

What you see there is a solenoid, and the other channel will be used for something a little bit different.

If the other circuit is for a loading mechanism, it's ok to say so. It's not a new concept..... it's been done before.

[PVC Arsenal 17]

What you see there is a solenoid, and the other channel will be used for something a little bit different.

If the other circuit is for a loading mechanism, it's ok to say so. It's not a new concept..... it's been done before.

Of course it's along those lines, but such things are rare around here. And I dare not brag about anything until I make it work successfully... which is going to be difficult even with all this stuff.

[velocity3x]

And I dare not brag about anything until I make it work successfully... which is going to be difficult even with all this stuff.

You'll get there. Successful or otherwise.....you should never worry about failure as it's an extremely important part of the learning process too. I'm pleased to see someone push the norm for new, more technical designs as opposed to those who only extoll their own genius /abilities yet, do nothing to apply / prove it.

Best to you in your endeavor

[Davidvaini]

what kind of voltage does it allow for the solenoids?

I myself thing that figuring out a very simple circuit to use an separate battery source would be ideal for most of the applications I would want to use the arduino for.

I seen this video, and I guess I am just still a little confused on how to actually wire it up..

[POLAND_SPUD]

I think I know what you want to find >>> http://www.arduino.cc/cgi-bin/yabb2/YaB ... 8931/10#10

[Davidvaini]

I think I know what you want to find >>> http://www.arduino.cc/cgi-bin/yabb2/YaB ... 8931/10#10

actually what I want is exactly what that video I linked to is... What I really want to know is exactly how to hook it up with an arduino...

particularly the grounding situation...

[Technician1002]

Be sure to take careful note of the use of the diode for motors and solenoids. Without it you will instantly destroy the mosfet. The inductance of the coil can create very high voltage spikes that exceed the rating of the mosfet.

[POLAND_SPUD]

What I really want to know is exactly how to hook it up with an arduino

Visit http://www.arduino.cc/playground/

http://www.arduino.cc/cgi-bin/yabb2/YaB ... 8931/10#10

The thing they found here is an integrated circuit that has several inbuilt solid state relays

http://en.wikipedia.org/wiki/Solid_state_relay

the cool thing about them is that >>>

Many SSRs use optical coupling. The control voltage energizes an LED which illuminates and switches on a photo-sensitive diode (photo-voltaic); the diode current turns on a back-to-back thyristor, silicon controlled rectifier, or MOSFET transistor to switch the load. The optical coupling allows the control circuit to be electrically isolated from the load.

I am pretty sure you can find all the info you need on http://www.arduino.cc/playground/
(for a start find why you've got to use resistors)

[Davidvaini]

What I really want to know is exactly how to hook it up with an arduino

Visit http://www.arduino.cc/playground/

http://www.arduino.cc/cgi-bin/yabb2/YaB ... 8931/10#10

The thing they found here is an integrated circuit that has several inbuilt solid state relays

http://en.wikipedia.org/wiki/Solid_state_relay

the cool thing about them is that >>>

Many SSRs use optical coupling. The control voltage energizes an LED which illuminates and switches on a photo-sensitive diode (photo-voltaic); the diode current turns on a back-to-back thyristor, silicon controlled rectifier, or MOSFET transistor to switch the load. The optical coupling allows the control circuit to be electrically isolated from the load.

I am pretty sure you can find all the info you need on http://www.arduino.cc/playground/
(for a start find why you've got to use resistors)

I don't want to hijack this thread.. but...

What I actually need is some way to understand the actual circuit diagrams. I am still new to electronics and everything Ive seen assumes you know what all the symbols mean and how to hook them up or atleast how to understand how to hook them up.. For example, I didnt know the symbol for a transistor, didnt know on the diagram what the drain, source, or gate was labeled as..

I need a practical diagram.. what this means is.. this wire goes here, this wire goes here.. I think it would help me understand the flow of things and also help me get interested and started with a simple project like this.

Also there are about a thousand ideas that I h ave that I could use if I learned this simple circuit. that video I posted seems like a really simple and straight foward example, but again, he doesnt show where the ground does, does the arduino and the circuit share the same ground? (for example when you hook up an LED to the arduino, you have a positive in one of the pinouts and you have the other end of the LED into the ground on the arduino itself.. )

I have checked out the playground and I run into the problem mentioned above...

If someone actually drew on a paint program this wire goes here, this part is a ____ and actually say what type.. (example a transistor).. I can figure it out from there.. I know what a field effect transistor does, I know the gate controls the switch and you have the source and drain, I know a resistor adds resistance to the ciruit, and I know a diode makes it so electricity can only flow in one direction, I know diodes are needed because of the coil and the problems with emf.. I just dont understand the dang diagrams.. lol

I also know exactly what to look for when it comes to a mosfet transistor, I need a N-channel, logic level (that way the ~5v) can actually activate the darn thing. I know it has to be able to handle the voltage and to have a good safety factor, and be able to handle said amperage.. I know that the higher amperage and voltage means I probably will have to apply a heatsink of some kind as a safety precaution..

What I have so far.. and I could be completely wrong.. is...

Arduino pinout goes to a logic level n-channel mosfet, the negative/ground of the 12v battery is hooked up to a 100k resistor, and then to the source of the mosfet, and the drain is hooked up to the solenoids negative end.. then the positive end of the solenoid is hooked up to the positive end of the battery...

thats as far as I got so far.. obviously the circuit is not complete and therefor would not work right now.. but I am wondering what I have listed is correct so far?


EDIT: I found this image and It really clears some things up for me..

http://www.digital-diy.com/digital-diy. ... 20Down.gif

just wondering, the ground that is hooked up to the resistor which is hooked up to the gate of the mosfet, does that mean it goes to the ground/negative of the 12v battery? or does it go the the pin labeled ground on the arduino?

and if it does go to the ground of the arduino, where does the negative/ground end of the battery go to?

[POLAND_SPUD]

there are dozens of tutorials there - I am pretty sure you can find everything you need there...

I just dont understand the dang diagrams.. lol

Have you heard of Yenka ? google it and download it

while it has nothing to do with arduino it should help you understand diagrams


ohh and I really think this IC makes things a lot easier -> http://www.components.omron.com/compone ... 1_1210.pdf

Just think how just a couple of them are needed to completely isolate the two circuits and power almost everything you want

[Davidvaini]

there are dozens of tutorials there - I am pretty sure you can find everything you need there...

I found a 2 links on there myself, one of them is broken and the other is in german or something.. lol


As their playground is very useful and I used it to understand some other simple circuits, this simple task that seems like it would be very common has escaped me..

I've been searching and it Seems like nobody has had a problem with power from the circuit interfering with the arduino with the setup in that picture that I showed above... the mosfet I am looking at can handle the voltage and amperage for all my needs. So I don't see why I need a relay in this case... I just need to figure out exactly how the ground situation and the battery situation and I got it!


I mean.. the ground labeled in that picture must be the ground of the battery...

I mean the mosfet is the same thing as on/off switch, its just electrically controlled (when it gets 5 volts it turns on)..

and if you look at any basic circuit with an on/off switch.. you have something like this...


with the ground of the switch going to the ground of the battery...

but where does the ground on the arduino hook up to?

[POLAND_SPUD]

Have you seen this > http://www.arduino.cc/playground/upload ... driver.pdf

anyway... most solenoid valves require 24V that's why I think that the IC is a better and neater way...

[Technician1002]

Many solenoid valves are 24 VAC. The transistor won't work with an AC supply. If you substitute the transistor for a triac (a type of back to back SCR) it will switch AC just fine.

If you use a Triac, substitute the MT1 for the Drain and MT2 for the Source Gate connects to the Gate if replacing a FET for DC operation. If replacing a BiPolar transistor, MT1 replaces the Emitter and MT2 replaces the Collector and the Gate replaces the Base.

The other option is to run the solenoid on DC power. Due to the current limiting provided by inductance of the coil, an AC coil will draw way more current on DC since the current limiting is due to resistance instead of inductance. Due to this, most 24 VAC solenoids will operate just fine on 12 VDC.

[PVC Arsenal 17]

My progress on this project has been halted because a motor I'm using is drawing an absurd 3.6 amps at full load, far too much for any normal motor shield. Fortunately I realized in my testing that I don't necessarily need PWM control over the motor and can get away with simple on/off operation, so another motor driver is not necessary. I will set up a circuit much like the one you guys have been discussing.

Unfortunately I'm stuck wondering the same thing as you, Davidvaini. Does the line running to ground on the battery also run to ground on the Arduino? Let me know if you ever found an answer to that, and please link me to the MOSFET you mentioned because it's likely that it will suit my needs as well.

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Edit: I believe I found the answer. YES, both ground on the Arduino and ground on the power supply are connected, but it's best to use separate wires. If not, the Arduino might reset when the motor is switched on due to high current building in that wire.

Similar things can happen if your motor's supply also powers Arduino, but I doubt you will do that.

Extremely helpful thread.



If all else fails, rig a servo to flip a switch. How's that for isolated?


Edit 2: I came across a real nice logic-level MOSFET that should suit our needs perfectly. Better still, there is a breakout kit available that gives you convenient screw terminals for all your leads.

[PVC Arsenal 17]

Well my problems are solved. I assembled the circuit for three feedback switches and two 30A logic-level MOSFETs onto a tiny breadboard. The electrical part of my project is just about done now, the rest is a matter of assembly. Unfortunately I'm forced to work in short installments during my time home from school, but progress will be made whenever possible.

I have to say I'm really starting to appreciate the fact that this is a micro-controller based design. Any flaws or odd scenarios that need to be accounted for can be worked out in seconds without touching a single wire or component.