Need help with a project, relay to control a DC motor

Thread Starter

circuitpachi

Joined Feb 8, 2024
16
Hi all, I am a beginner at this. How do I connect a 12 volt source (red +, black -) NPN NO 3 wire sensor (brown +, blue -, black) to a JD1914 4-pin relay to control a DC motor (red +, black -)? I want the NPN NO 3 wire sensor to control the DC motor through the 4 pin relay. Color coding and configuration would help me.
 

BobTPH

Joined Jun 5, 2013
8,989
Welcome to the forum.

We will need much more information to help you.

1. Type and model of sensor. datashhet link.

2. What does “control the motor” mean? Direction? Speed? On/off?
 

Thread Starter

circuitpachi

Joined Feb 8, 2024
16
Need more information about the sensor and the relay. Manufacturer / part number / web page / internal schematic / datasheet - Anything - ?

ak
LJ12A3-4-Z/BX NPN sensor with a brown black and blue wire. https://www.aliexpress.us/item/3256806155262074.html?spm=a2g0o.productlist.main.39.43eb33caVqIuxS&algo_pvid=7827315d-3020-431b-a505-73a55d713052&aem_p4p_detail=202402081538042735956049477220002503955&algo_exp_id=7827315d-3020-431b-a505-73a55d713052-19&pdp_npi=4@dis!USD!1.66!0.90!!!1.66!0.90!@2101ead817074354842426055ef96b!12000036823200954!sea!US!2533244618!&curPageLogUid=K0w4znlinHJM&utparam-url=scene:search|query_from:&search_p4p_id=202402081538042735956049477220002503955_4


JD1914 5 pin relay https://www.aliexpress.us/item/3256806080772573.html?spm=a2g0o.productlist.main.1.10d2ae50e91JT6&algo_pvid=35068d8d-69a4-44d5-863e-6311de459940&algo_exp_id=35068d8d-69a4-44d5-863e-6311de459940-0&pdp_npi=4@dis!USD!4.35!2.04!!!31.21!14.67!@2103251f17074354315747958e329f!12000036534384570!sea!US!2533244618!&curPageLogUid=zugbRjEk27Qa&utparam-url=scene:search|query_from:


DC 12 Volt Motor. https://www.aliexpress.us/item/2251832702879295.html?spm=a2g0o.productlist.main.13.8d68658d6XAitE&algo_pvid=7c79e2b0-0924-4a15-a760-3d614af1bd2e&algo_exp_id=7c79e2b0-0924-4a15-a760-3d614af1bd2e-6&pdp_npi=4@dis!USD!15.54!11.50!!!15.54!11.50!@2101ead817074355309026918ef96b!67506194504!sea!US!2533244618!&curPageLogUid=ci8oigTJaZXz&utparam-url=scene:search|query_from:

My goal is to get the sensor to trigger the motor via the relay. I have all of the equipment necessary including the wire and terminals.
 
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Thread Starter

circuitpachi

Joined Feb 8, 2024
16
Welcome to the forum.

We will need much more information to help you.

1. Type and model of sensor. datashhet link.

2. What does “control the motor” mean? Direction? Speed? On/off?
LJ12A3-4-Z/BX NPN sensor with a brown black and blue wire. https://www.aliexpress.us/item/3256..._id=202402081538042735956049477220002503955_4


JD1914 5 pin relay https://www.aliexpress.us/item/3256...RjEk27Qa&utparam-url=scene:search|query_from:


DC 12 Volt Motor. https://www.aliexpress.us/item/2251...igTJaZXz&utparam-url=scene:search|query_from:

When the sensor is triggered I need it to signal to the motor. When the sensor is no longer triggered I need the motor to stop.
 

AnalogKid

Joined Aug 1, 2013
11,053
Lacking a complete datasheet, my g.u.e.s.s is that the sensor has an open-collector output that, with the NPN device, can sink 300 mA. The relay current is 142 mA at 12 V, so it looks like the sensor can drive the relay directly (with additional transient protection).

ak
 

Thread Starter

circuitpachi

Joined Feb 8, 2024
16
Lacking a complete datasheet, my g.u.e.s.s is that the sensor has an open-collector output that, with the NPN device, can sink 300 mA. The relay current is 142 mA at 12 V, so it looks like the sensor can drive the relay directly (with additional transient protection).

ak
How would you set up the wiring?
 

Thread Starter

circuitpachi

Joined Feb 8, 2024
16
I think I figured it out. I think it was an unstable connection.
So I came back to the project today. I have found that the clicking in the relay is still sporadic despite making sure all the connections are secured properly. I googled clicking of the relay and I found articles saying there is not enough output voltage to sustain the load. I am using a 12V 2A power source from the wall socket so there shouldn't be any issue there.
 
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Thread Starter

circuitpachi

Joined Feb 8, 2024
16
So I came back to the project today. I have found that the clicking in the relay is still sporadic despite making sure all the connections are secured properly. I googled clicking of the relay and I found articles saying there is not enough output voltage to sustain the load. I am using a 12V 2A power source from the wall socket so there shouldn't be any issue there.
I have found when I apply pressure to the motor (increasing the torque) the clicking in the relay begins and the power source LED blinks with the clicking. What could be the cause of this?
 

Thread Starter

circuitpachi

Joined Feb 8, 2024
16
I have found when I apply pressure to the motor (increasing the torque) the clicking in the relay begins and the power source LED blinks with the clicking. What could be the cause of this?
Never mind, It does the same thing with or without the load. I find it may have something to do with the 85 pin. Going to mess around with it and see what it does
 

LesJones

Joined Jan 8, 2017
4,190
I think you will find that the output voltage of the power supply is dropping due to the current drawn by the motor. Monitor the voltage and current when the motor is under load.

Les.
 

Thread Starter

circuitpachi

Joined Feb 8, 2024
16
I think you will find that the output voltage of the power supply is dropping due to the current drawn by the motor. Monitor the voltage and current when the motor is under load.

Les.
Can you help me understand this table? The stall and turn. Is that the amps it requires to push against resistance from a stop? Im confused bc i have another motor that does fine with a 12V2A except its on a solid state relay rather than a 5 pin relay.
 

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Thread Starter

circuitpachi

Joined Feb 8, 2024
16
If the relay is clicking with no load on the contacts it's not the motor.
Does the motor run fine connected to the power supply directly?
Do you have a voltmeter for testing? Helpful if testing is done in stages
Motor runs fine when power is supplied directly. I will try to send a link of the video. I have a voltmeter somewhere just have to find it. https://drive.google.com/file/d/1gwtH311W-NX5lE2Y06WsvSw1V2Lk_KtD/view?usp=drive_link
Sorry about the messy workspace.
 
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Thread Starter

circuitpachi

Joined Feb 8, 2024
16
Now connect the relay directly to the power supply. Negative to pin 85 and Positive to pin 86 and see what happens.
Single click when I connect power directly to relay with pin 30 disconnected. When I connect pin 30 directly from the positive terminal it does the repetitive clicking again.
 
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