reel-to-reel Omron relay help

[theminkey01]

Could someone help me understand how this one relay (K401) works in this circuit? I don't understand how points 7,10, & 12 control this relay.

This looks to be a 4PDT DC24V Omron relay. Labelled K401 in the jpeg and highlighted yellow. The actual part has this writing on it : Omron Type MY4 -02-US-L DC24

The relay controls those 4 switches above it in yellow. They are shown in the off position. What they are switching was left out for clarity and it doesn't really matter. Except for the first switch, not sure what it is doing.

I wonder if I even need connection 7.

Ideally I just want one button to activate this relay from the power supply shown in the jpeg.

Any ideas on how to modify this circuit?

Thanks!

 

[theminkey01]

I found out that this comes from a standard latching relay circuit.

Check out this new revision, attached.

The momentary N.O. button when pressed will activated the relay and lock it on by using its own 1st switch. The momentary N.C. button will then reset the switches back to off when pressed.

Does this new circuit look right to you? Polarity ok? Buttons ok? Does that diode,resistor, and cap look right?

Any ideas?

Thanks!

 

[Arch Stanton]

Yes, it is correct.
There is also some kind of timer on the circuit.

 

[JonSnell Electronic]

Yes, it is correct.
There is also some kind of timer on the circuit.

The capacitor stops contact bounce.

 

[Arch Stanton]

The capacitor stops contact bounce.

Not only.
A diode does that job better.

 

[theminkey01]

Would you recommend changing that capacitor to a flyback diode? This would eliminate voltage spikes and bounce?

I don't need any timing thing.

What does this current D19 diode in the circuit do?

Thanks!

 

[Arch Stanton]

Yes the reverse diode on the coil eliminate the spike fully.
But I do not understand the function of D19.

 

[theminkey01]

Cool. Thanks! I attached the latest revision.

Now for the power supply!

Take a look at this attached jpg and the original jpg schematic from the first post. Is this the right power supply circuit to extract and use for the relay?

 

[Arch Stanton]

Your set switch is not connected at the good place.
The power supply seems ok.

 

[theminkey01]

Is this a better set button location? jpg

Can you tell what the DC volts would be from this power supply circuit? Those diodes 3-6 are SIB01-02 part #.

 

[Arch Stanton]

The set switch must be connected in parallel with the NO switch of the relay.
The reset switch in serial with this combo.

The power supply will give roughly 32 V without load.

 

[theminkey01]

Like this? attached

Is 32V too much? This relay says 24V and I believe the ohms are around 636. Relay part number listed in first post if you need to look up specs.



Thank you for the help!

 

[Arch Stanton]

The switches are OK now !
You can increase the value of the resistor to decrease the voltage, beware of the power dissipated by it.

 

[xpa123]

In the original circuit, the diode, resistor and capacitor has two effects: 1) it delays the operation of the relay slightly and 2) it extend the time the relay is pulled in. This may be critical to the operation of some other part of the circuit. True, the capacitor absorbs the flyback when the coil releases, but it is not the only function.

 

[theminkey01]

Yay!!

How about a 200 ohm resistor?

* resistor 200 ohms, 7.66 volts, .293 watts
* relay 636 ohms, 24.34 volts, .9315 watts


Resistor power dissipation ok?

Volts on relay ok? Or less?

Thanks!!!!!!!!!!!!!!!!!!!!

 

[Arch Stanton]

A 1 W resistor can do the job without too much heath.
You can also use a 1 W Zener in series with the relay.

 

[Arch Stanton]

In the original circuit, the diode, resistor and capacitor has two effects: 1) it delays the operation of the relay slightly and 2) it extend the time the relay is pulled in. This may be critical to the operation of some other part of the circuit. True, the capacitor absorbs the flyback when the coil releases, but it is not the only function.

You are right, I said that in the third post.
Maybe it is negligible.

 

[theminkey01]

Just had a worry here. Do you think this setup will be ok with just push buttons like the latest jpg? I was wondering how long the relay takes to latch. Would it be possible to not push the buttons long enough to engage and disengage? This might be a problem if someone does not hold the button on long enough? Maybe this would be the reason for some capacitor setups, to have a minimum time.

Thoughts?

 

[Arch Stanton]

I think you are right.
Why do you want to modify the original design ?

 

[theminkey01]

Well the original design is for an entire reel-to-reel circuit. I only want to use this relay by itself.

I saw some Omron specs that say 20 ms max operating time and 20 ms max release time. If I'm understanding this correctly I think it is ok. I don't believe you can manually push the button faster than that.