1. P

    Use NPN NO Proximity Sensor to activate relay

    Hi All, It's been a long time since the high school electronics classes doing circuit design. I have a CNC router and need to connect up 2 Proximity Sensors to the one GPIO input. I have tried connecting them in series, but I am only getting a 12V trigger signal with 24V supply. So I thought...
  2. MrsssSu

    Why my Relay short-circuited ?

    I have a relay but rated at 3A, 30V DC only similar to this. When I connect the Pole and NC directly using a lithium ion battery (4V), a fire occur and it shortcicruicted. However, when i measure the resistance betwwen 2 pins (Pole and NC), it reads 16 Ohms. What should i do :) ? Thank you for...
  3. electromeow

    Relay or MOSFET for high current?

    Hi, I have to switch a high current(DC 12V@~60A approx.) for a battery-supplied circuit. But its on-status resistance should be as low as possible. Because you know the Ohm's Law, the I is going to increase up to even 100 amps sometimes, so a very small resistance creates a big difference. I...
  4. S

    Protecting transistor from DC motor/Relay current spikes

    I setup two small circuits on breadboard with BD139 transistors to drive a 12v 0.2A motor and 24v 0.15A Relay to learn transistors, I can switch ON transistor through base resistor using 3.3v PSU. I know when motor/relay stops it can push back some current and i believe its called current...
  5. masynthetic

    switching inductive load crashes microcontroller

    I am using an Arduino mega to switch several of these very common relays with a 24v inductive load on pretty much all of them and I am having a peculiar and extremely frustrating issue where during switching (frequently but not always) the Arduino will reset, when monitoring the arduino's 5v...
  6. RobyRoberto

    H3FA relays

    Hi. Wanted to change a couple of small power relays on a washing machine. Can anyone help me and guide me if the relays I got for replacement HF3FA 012012-ZTF(335) are compatible with the ones on the PCB? (H3FA 012-ZTF(088) I cannot figure out the datasheets for either of this. Cheers!
  7. E

    Controller gets hang on Relay switching

    I am using a relay to turn ON/OFF the AC load. But when i turn ON and turn OFF the AC load (230 VAC) 3-4 times my controller gets hang. Here is my circuit diagram for the relay. The ground is common in all over schematic. What changes do I need to do for improving the noise?
  8. D

    Solid State Relay Design For 24VAC

    Hi All I am new to the forum. I am working on a project, where i need to control 24VAC solenoids using my microcontroller. Previously i have used standard bulkier relays, but i now need some thing much smaller in design, therefore aim to use the AQH2213AX SSR. Can anyone advice, if the design...
  9. 2

    Momentary to control on & off circuit

    Hi everyone. As stated I am trying to figure out the easiest way to make a momentary switch control button control the on and off for my 12V lights I have on my vehicle. I know the very basics of electronics, I currently have the lights powered by two different switches on relays. Longer story...
  10. sofitens

    Wiring a NC relay for an AC condenser fan

    I'm planning for a project where I need a NC relay with a 24 VAC coil to disable my AC condenser fan, and I could use help selecting a correct relay to use and ensuring it's wired correctly. The condenser fan (OFM in the 1st diagram) is pretty typical with 3 wires, 1 coming from the contactor...
  11. S

    Turn 6V motor on/off via 555 timer astable circuit and 5V relay

    I have been working on a circuit to turn a motor on for several seconds, and then off for a longer period, using a 555 astable circuit. The on time needs to be around 5-10 seconds, and the off time needs to be about a minute. To get around the 50% duty cycle issue and allow for a longer off...
  12. Genosphere

    Trouble: Simulator expectations vs constructed circuit; 555timer.

    So I am having some trouble building the circuit I had built in a sim, several to be exact, which all seemed to work the way I wanted them to. Now that I have built the circuit on a board, Im not getting the results expected. Checked wiring and and parts, things look ok. Odds are I have missed...
  13. W

    Raspberry Pi triggers relay before power is turned on.

    I bought a relay like this today for my raspberry pi, and I am encountering a very strange issue. I connected the 5v output to the VCC pin, the ground to ground and a GPIO pin to the IN pin on the relay. I opened python and assigned 'led' to 'LED(15)', which is very standard. THAT triggered the...
  14. S

    RC snubber circuit for 220V AC solenoid valve

    Hello fine people! I've got a 220v AC solenoid valve which I want to control through a 5v relay module with rasp pi. As I've understood, I have to add an RC snubber circuit in series in order to protect the relay. And this is where I need help. I need to figure out what resistor and what...
  15. flipper2222222

    IR infra red frequency convertor

    hi everyone, not sure if this is even possible, maybe someone knows of a way. I have a IR blaster that sends at 38kHz and a device that has a 37kHz infra red system. is there a IR convertor \ relay that can make the receiving device (cable set top box) accept the commands of the sending...
  16. qwaspen

    Car fan auxiliary heater

    Hi! Got a problem with my auxiliary heater. I connected an auxiliary heater to my car and everything was working great. However, when I added the wiring harness for the car fan, it won’t work. I can only measure 5v at the relay, which is odd since it should be 12v. In addition to this, the car...
  17. W

    What does the datasheet say about the relay?

    I'm busy with a project that uses a Raspberry Pi zero and a relay. I've tried 2 relays and neither worked. I'd like some help to understand how to choose the correct relay, as well as which one will work. First, I used this one: SSR-100DA. I connected the input to the Pi, and the output to my...
  18. M

    Wireless RF Relay Project: 12 Fish Feeders, Low DC Voltage Circuits

    Hi Everyone, Project Goal: Feed my fish! Tidy up and get rid of conduit and wires running eveywhere! Current Setup: I have 12 Fish Feeders powered by a DC motor, and I run all the wires run along the walls in conduit back to the controller. Each color represents one fish tank. ("1-4" feeder...
  19. G

    Two LEDs and 2 SPST. Four states?

    Hello, Newbie question I have a device that have two SPST relays that I control. From these relays, I would like to control the ON/OFF states of two LEDs (red and green) and a high/low brightness state. This gives four possibilities: Red High brightness Red Low brightness Green High brightness...
  20. snajperisti

    Snubber Circuit Design 230V, 16A, Problem in small load, Current Flow!

    Hello We designed this Snubber Circuit with this varistor in parallel but we have a problem in a small load. Even when the relay is disconnected, a small current is flowing. For example, when connecting a phone charger, the phone screen keeps turning on and off. The varistor is Hongzhi Elec...
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