Resistors + Ohm's Law.

Thread Starter

Bod

Joined Sep 18, 2016
317
Sorry I gave you the wrong code. Search: omron g2r-1. My relay will come up. Make sure its a 5v one.
 

mcgyvr

Joined Oct 15, 2009
5,394
An Omron relay. It does not say what current, but I would of thought its not that high.

Yes correct.
Its momentary.
Yes just to turn it on.
No, its a 6 - 15V DC motor and using a 3pin switch I am supplying it 12v on one output. And unfortunately only 5v on the second.
Its a MFA Como Drills motor. Specs: http://www.mfacomodrills.com/pdfs/Miniature DC motors.pdf Mine is the RE - 360 (3 POLE) & RE - 360/1
There are no specs, just a generic switch but with two metal pads and when you place your fingers on both pads you become the connection.
This is still making little sense to me..
Now you have a 5V source too? So you have a 5V a 9V and a 12V power source?
Where does this 3 pin switch come into play?
Do you only want the motor to run when you hold down the momentary switch or do you need some "latching" so pressing and releasing the momentary turns the motor on and pressing and releasing again turns the motor off?
 

bertus

Joined Apr 5, 2008
22,928
Hello,

That is quite a heavy relay.
The current for the coil is 106 mA as per table:

G2R-1_coil_data.png

To drop 4 Volts at 106 mA , you will need a resistor of 4 / 0.106 = 37 Ohms.
39 Ohms is the closest standard value.
The resistor should be an 1 Watt version as almost 0.5 Watt needs to be dissipated.

Bertus
 

Thread Starter

Bod

Joined Sep 18, 2016
317
This is still making little sense to me..
Now you have a 5V source too? So you have a 5V a 9V and a 12V power source?
Where does this 3 pin switch come into play?
Do you only want the motor to run when you hold down the momentary switch or do you need some "latching" so pressing and releasing the momentary turns the motor on and pressing and releasing again turns the motor off?
Yes 5v, 9v and 12, supply (9v is a battery) But the 5v supply is pretty irrelevant.
3 pin switch is to change the speed of the motor.
I do want "latching" for the momentary switch.
 
Last edited:

mcgyvr

Joined Oct 15, 2009
5,394
Is switch normally closed or normally open?
Rest of the relay part number?
What other components do you have? You will need more for latching (or just buy a regular toggle switch instead)..
How long must the battery last?
Can you switch to a 3 or 4 AA batteries in a pack?
 

Thread Starter

Bod

Joined Sep 18, 2016
317
Is switch normally closed or normally open?
Rest of the relay part number?
What other components do you have? You will need more for latching (or just buy a regular toggle switch instead)..
How long must the battery last?
Can you switch to a 3 or 4 AA batteries in a pack?
It's normally open.
The relay part No is just what I said: g2r-1. The other one I gave you - 2656H1 - won't bring anything up.
What other components do you need for a latching device? Wont a relay do it?
The battery will last as much as it can, there is no specific runtime.
Yes I could switch to 3 - 4 AA Batteries, but whats the difference?
 

atferrari

Joined Jan 6, 2004
5,012
It would help if you simply detail the problem you need to solve and no the idea you have in solving it. Takes time to reach a valid solution.
 

Tonyr1084

Joined Sep 24, 2015
9,744
I, too, have a hard time understanding where this is going. So far in my brain is a collection of parts thrown into a bag and shaken vigorously in the hopes of solving a problem that has yet to be identified.

So here's what I can come up with: Take a thing and hook it to a thing so that when the things start to do their thing the third thing begins to respond and solve the need by doing that thing for which you are trying to design a thing for.

Sorry I can't be any clearer, but your post can't be any muddier. PLEASE take the time to answer all the questions that have been posted and PLEASE tell us what it is you're trying to do. If you're trying to use a motor to wind up a cuckoo clock - say so. If it's to run a shaver - say so. If it's to remove the snow from your driveway - please say so. Only when we understand the problem can we begin to help you solve the problem. Note that I said "can WE begin to HELP YOU solve the problem. If you want us to engineer something then you can start writing checks to those who work on your problem. But if you want help solving YOUR problem, that's what we're here for. To HELP YOU solve the problem. Not to solve it for you.

Please tell us everything you can about what you want to achieve and what you have to do it with. Tell us what your proposed solution is so we can help you understand how to change your design. So far I saw a 7 segment display, a relay, a battery of some mysterious voltage, a motor from a drill (I think), and a relay that works on 5 volts. The ONLY useful piece of information you've give us is the 5 volt relay and its part number. Beyond that everything else is just guesswork and ambiguity. We need clarity or we can't help. And none of us want to solve it FOR you. We'll HELP you. But you need to help us help you.
 

Thread Starter

Bod

Joined Sep 18, 2016
317
@Tonyr1084
I agree with this being a very unclear post, but I have got the answer so yeah I guess.

But anyways, thanks for saying that, I will definitely take this into consideration in the future.

- Bod
 

hp1729

Joined Nov 23, 2015
2,304
Here (it's not very accurate as I could not find the exact components)
View attachment 118145
Common Anode or common cathode display? Check the data sheet for the display. It may only need about 2 Volts, not 5. No data? Start with as high resistor (1,000) and note the voltage across the display. Lower the resistor value to achieve the desired brightness. For, say 10 mA at 2 V across the display, from a 9 V battery your calculation is 7 V / 10 mA. So a 680 or 750 ohm resistor. No precision required.
Your drawing is good. you plan to move the ground wire around to light different segments?
 

Phil-S

Joined Dec 4, 2015
241
A nice example of a lot of effort going into a low grade specification - was an LED or was it a relay? Still not sure. The OP wasn't sure.
I can think of certain forums where this wouldn't get out of the starting blocks. Luckily, AAC folk are nice patient people.
 
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