Questions tagged [solenoid]

An electromagnet combined with an actuator to convert electrical energy into linear physical motion.

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25
votes
4answers
12k views

Why aren't solenoid/electromagnet windings insulated?

This has been bugging me for a long time. Take this video for example. I have always thought that electricity will take the shortest path. When the electromagnet's windings are uninsulated, it seems ...
22
votes
4answers
10k views

Why did my fuse blow after 3+ years of no problems?

For several years, I've had a solenoid wired to the 24VDC output of a PLC (Rockewell Automation 1769-OB16). To protect the PLC output card, a fast-acting 500mA fuse was installed between the PLC and ...
18
votes
3answers
2k views

How critical is winding a solenoid/electromagnet neatly?

We've all seen the expensive toroidal winding machines on YouTube, and manufactured solenoids are always so neat in construction - as in: Each winding is neatly packed to its previous, without ...
15
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4answers
56k views

How to properly wind coils for a solenoid?

I need to wind a small electromagnet "solenoid?". About 3cm high and 2~5cm wide running at 5V/0.5A. This magnet will be put into a desk bell so it pulls the clapper down and rings the bell. I have ...
14
votes
6answers
22k views

My MOSFET operated solenoid circuit destroys my Arduino inputs

I made a series of PCBs to power some solenoid valves that use an external power supply. I switch them with BS170 MOSFETs using an Arduino as gate signal. I based it a solution by Jason S. This is an ...
12
votes
3answers
617 views

Electrocuting a fruit fly using magnetic induction

We are electrically inducing heart attacks in fruit flies to test the effects of various treatments on survival. We are shooting for roughly a 50% survival recovery rate in our control group. I work ...
11
votes
5answers
2k views

MOSFET broke after attaching capacitor bank

I have a solenoid that has a coil resistance of \$0.3\Omega\$ and accelerates a steel projectile here. I've posted the schematics below. Normal Version that acts as a control The GPIO8 goes to 5V to ...
11
votes
1answer
3k views

Is there such a thing as an ultra low power solenoid?

I am looking for a tiny push-type solenoid that can be driven with milliwatts. The plunger need only move 2-3 mm. Does such a thing exist?
10
votes
2answers
6k views

Do solenoids exhibit back EMF like motors?

I just purchased some pinball machine solenoids and was experimenting with them; DC resistance is about 30 ohm, they actuate at about 30 volts, and they hold at about 6. I tried controlling them with ...
9
votes
8answers
501 views

Measuring the activation time of a solenoid

I'm trying to measure the activation time of a pull-type solenoid. When the solenoid doesn't have a load connected to it, you can measure its activation time through the current it consumes. At first,...
9
votes
2answers
550 views

Electrical behavior of holding magnets when you pull them apart

I'm going to buy a holding electromagnet and a strike plate to hold some things, and I want to design my circuit (arduino-controlled) not to fry like bacon. I'm aware that since a holding magnet is ...
8
votes
3answers
6k views

Why is this reed switch / solenoid circuit not working?

The (normally open) reed switch should close by waving a magnet across it, completing the circuit. The 6v solenoid lock should pull inwards allowing the door to be opened. When the magnet is removed ...
8
votes
3answers
4k views

changing direction of solenoid

note I know essentially nothing about solenoids I brought this solenoid thinking that I could use it to hit an object, but when I put it to a power supply, the only direction that it would go is down....
8
votes
2answers
293 views

Can Solenoids Get Sticky From Improper Usage?

I bought three spring-return, push-type solenoid. I can't remember them being sticky from the start because I only was using one at a time, but they may have been. Now that I tried to work them ...
7
votes
8answers
2k views

Strange behaviour in PCB when solenoid turns off

Hi all, I designed a PCB for a lock control. You can see the PCB on the image. Some explanation on the abbreviations: Ext: exterior 12V power source Batt: 12V battery 1702: 12V to 5V power converter ...
7
votes
2answers
8k views

Driving Solenoids from Arduino

I was wondering what the best way to run a solenoid would be from an Arduino board. I was thinking about using a MOSFET that runs into a relay to turn on the solenoid but am not sure how to go about ...
7
votes
2answers
17k views

Solenoid Driving Circuit

I'm trying to drive a 12v (14W) solenoid and have problems figuring out the components for the driving circuit. The solenoid draws about 1.166A and the MCU is being operated at 3.3V. I've seen many ...
6
votes
5answers
2k views

Solenoid fastest possible release - for how long should reversed polarity be applied?

If I understand correctly, a regular solenoid like this one does not have a permanent magnet as core and as such it doesn't matter with what polarity it is activated (please correct me if that's ...
6
votes
5answers
2k views

Automated test for pushing a pcb mounted mini push button

We have a test that checks whether or a push button works or not, and as of now the test is done manually by hand. My question is how to do this automatically? We have considered using a solenoid to ...
6
votes
4answers
923 views

TIP120 Transistor + Solenoid Failing Randomly

I am using TIP120 transistors (controlled by 74HC595 shift registers) to control 12VDC, normally closed solenoid valves. Everything is working in short-time tests however when left overnight, some ...
6
votes
2answers
3k views

Flyback protection for a DC latching solenoid?

I'm looking for a solution for "flyback" protection when driving a 2 wire DC latching solenoid. You cannot use the traditional diode solution as the polarity of the coil is reversed to open or close ...
6
votes
3answers
2k views

Solenoids causing Arduino to malfunction despite protection diode

simulate this circuit – Schematic created using CircuitLab I have an Arduino Mega that I'm attempting to control some solenoids and LEDs with. The LEDs are 3.3V, controlled through an open ...
6
votes
6answers
8k views

What would a professional use to switch sprinkler solenoids?

As evidenced by several previous questions of mine, I'm working a project to design a sprinkler controller. This involves driving one of 16 solenoids (well, probably only one at a time...) based on a ...
6
votes
2answers
5k views

How can I prevent a 556 timer IC from becoming very hot?

I built the circuit described in a previous question/answer which I will repost here: It's been running quite well, actuating the solenoid at regular intervals as designed. The TIP122 transistor is ...
5
votes
7answers
12k views

Long solenoid (50cm stroke)

I need to move a rod with a 50cm stroke. Almost no force is needed(the rod is just for display purposes). Speed is also not essential. I was thinking of creating a very long DC solenoid but I am ...
5
votes
7answers
6k views

How can I control 128 (or more) solenoids?

I need to switch 128 solenoids either on or off individually, several times a second. I'd like to drive this from either a PC, or an embedded device. How would you recommend I do this? Perhaps ...
5
votes
5answers
10k views

Inductor in-rush current

The inductor equation V = L(di/dt) shows that inductors will resist instantaneous changes in current. Thus, they can be used as in-rush current limiters in power ...
5
votes
1answer
2k views

How an AC electric magnet works?

I want to know how an AC electric magnet works since the polarity of an AC current changing 100 times in each second (for 50Hz mains supply) so its magnet polarity(N & S) also will changed 100 ...
5
votes
2answers
7k views

555 timer in astable mode: How can I achieve longer low output than high?

I'm attempting to make a simplistic solenoid driver circuit using a standard astable 555 timer configuration with a TIP122 NPN transistor. The problem with the current circuit is that the output is ...
5
votes
3answers
3k views

From what used/junk equipment can I salvage solenoids from?

I have a few old 24V solenoids which I've used for years for random (often Halloween-related) projects. I can't recall where I got them. I'd like to get some more, but new ones can be rather high ...
5
votes
3answers
2k views

Choosing a MOSFET for solenoid control via Arduino

I'm trying to drive a solenoid I took off an old pinball machine with an Arduino. The pinball machine ran on 25 V AC and I've found that the solenoid was 2 Ω online (so 12.5 A). The Arduino puts out 5 ...
5
votes
2answers
604 views

Switching inductive loads at long distances - best practice

This question focuses on the switching of inductive loads at a relatively long distance, specifically on handling the inductive kickback as a result of switching. The inductive load in question is an ...
5
votes
1answer
3k views

AC solenoid valve with DC

I have a 24VAC/60Hz solenoid. I used 12VDC just to try, and it worked good (well needless to say it worked as expected with 24VAC/60Hz). What are the effects of a solenoid that's designed for AC ...
5
votes
4answers
8k views

How to decrease solenoid speed?

My project is Speed Control of a solenoid. In this project, stroke is 30 mm and I want to plunger cross 30mm in a few seconds (like 5 seconds). For this purpose I want to control the current of the ...
5
votes
1answer
11k views

Connecting microcontroller 3.3V output to relay using ULN2803A

I have a need to connect an ARM micro-controller with 3.3V digital output pins to a few 12V solenoid water valves. I figured that I can use a ULN2803A for this task. The internal circuit for each ...
5
votes
2answers
1k views

Considerations for powering solenoid and arduino from the same power supply

I'm working on a project where I will need to power a small solenoid (probably 12V) and an Arduino Pro Mini 3.3V (3.3-12V input, onboard circuitry regulates to 3.3V). I'm thinking about using an H-...
5
votes
1answer
2k views

Circuit to control a impulse solenoid valve from a movement detector

I have a movement detector sensor that generate a pulse (3.3V TTL) for 60 seconds when something moves in front of it. On the other hand, I have a impulse solenoid valve that close on a negative ...
5
votes
1answer
481 views

How to estimate inductive coupling between distant air coils

I have two air coils. They both have diameter d. There is a distance D between their centres. D is much greater than d (more than 10x greater) Both coils are at different angles, a and b, relative ...
4
votes
6answers
2k views

Using a PNP over an NPN to activate a solenoid

I am working on a circuit that controls a solenoid through the use of an Arduino. One question I had was if there was any advantage to using a PNP transistor over an NPN transistor? From class, I know ...
4
votes
4answers
997 views

My shift register is working when I use LEDs, but not a solenoid

I'm trying to operate a solenoid push pull motor with a shift register. It works fine with LEDs, but when I try to use the shift register to trigger my solenoid it doesn't work. I suspect it's a power ...
4
votes
4answers
994 views

How to build a programmable sticky button

I'm trying to build a button that can exist in two modes. Either it springs back after being pressed, or it stays pressed. I want to switch between these two modes using some complex logic, controlled ...
4
votes
3answers
1k views

How does the size of a reservoir capacitor affect battery life?

I have a circuit, powered by a 9V alkaline, where a solenoid is actuated via a MOSFET. I have a large reservoir capacitor (4700uF electrolytic) on the high side of the solenoid. I was wondering how ...
4
votes
2answers
2k views

MOSFET or bipolar to drive a solenoid valve?

I have to drive a 12V solenoid valve. In the datasheet it's written: Power: 8 W. So the current drawn by the solenoid is 0.666 A. Usually, to drive small relay (about 10 or 20 mA) I use a bipolar ...
4
votes
2answers
513 views

Resonant Solenoid Drivers

Over the years I have always wondered why we do not make more use of resonance when driving things like solenoids and relays. We all use the circuit below ad-infinitum and just tolerate the current ...
4
votes
2answers
23k views

How much force does a solenoid really have?

This hopefully isn't too off topic for this forum, but here goes: after many days of tinkering I managed to get a circuit working that, in the end, energizes a solenoid to pull a lever. Sadly, even ...
4
votes
3answers
1k views

Which of the following methods should I use to actuate a solenoid from a microcontroller?

I've been studying the PICAXE microcontroller as a driver for a set of three 12VDC solenoid valves (though I may choose the 24V models). For reference, the controller will use a temperature sensor to ...
4
votes
2answers
6k views

Control 12 solenoids with a raspberry pi

I'm a musician and I'm working on a funny project : control solenoids with a midi keyboard. So I have a MIDI keyboard connected to my raspberry pi connected to my breadboard. Until now everything is ...
4
votes
2answers
3k views

How to make a solenoid armature travel at a faster rate of speed?

My project requires a solenoid with a stroke of 15mm and the travel speed must be 15mm in 2ms. What can be done to get higher speed of travel in the armature?
4
votes
2answers
11k views

Can I use a solid state relay to control a DC current?

Can I use an AC solid state relay to control a DC current as long as the DC voltage doesn't exceed the rated AC voltages? I want to control a solenoid but I'm concerned about the inductance problem ...
4
votes
2answers
1k views

Suggestions on board designing, ground plane and layers - PCB images

I'm designing a board (with EAGLE) for my first time and, before posting here, I've read some topics and documents on how to design a board, but I still need help since I'm a beginner. My board ...

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