Any EE's on here

[Todd#43]

I've got a question for any electrical engineers:

What can I use to create a 100 MS delay between two 220 V contactors?

Ask away if you've got any questions.

[NinjaNick]

JarvisMB is one. He'd help you out, but that's if he gets on here over the weekend.

[Todd#43]

Thanks Nick.

Maybe he'll see this.

[Todd#43]

Edit...

My bad, the contactors are 110V.

[flounder]

12oclocker could fix ya right up.

[NinjaNick]

Yep, 12 too. With it being holiday, you might not get their attention probably until Tuesday. Just like a cop, when you need one, they're never around.

[NinjaNick]

Hey Todd, I'll text 12oclocker on my phone and see if he can help you out.

[12oclocker]

there are a lot of ways to do it, how exact does the 100ms delay have to be, are you driving a relay?, whats the ckt for?

... you could charge a capacitor to trigger a transistor which triggers a relay using a RC time constant formula to obtain the 100ms (not super accurate, could fluctuate slightly)

... you could use a 555 chip which is capable with doing 100ms timings (also not super accurate, could fluctuate slightly)

... or you could use a cheap microcontroller chip to trigger a relay or SCR, (most accurate, but adds a few dollars to the cost and complicates the design, but if exact timing is needed, its a good solution.)

[Goldie]

there are a lot of ways to do it, how exact does the 100ms delay have to be, are you driving a relay?, whats the ckt for?

... you could charge a capacitor to trigger a transistor which triggers a relay using a RC time constant formula to obtain the 100ms (not super accurate, could fluctuate slightly)

... you could use a 555 chip which is capable with doing 100ms timings (also not super accurate, could fluctuate slightly)

... or you could use a cheap microcontroller chip to trigger a relay or SCR, (most accurate, but adds a few dollars to the cost and complicates the design, but if exact timing is needed, its a good solution.)

Yeah, what he said

[Todd#43]

there are a lot of ways to do it, how exact does the 100ms delay have to be, are you driving a relay?, whats the ckt for?

... you could charge a capacitor to trigger a transistor which triggers a relay using a RC time constant formula to obtain the 100ms (not super accurate, could fluctuate slightly)

... you could use a 555 chip which is capable with doing 100ms timings (also not super accurate, could fluctuate slightly)

... or you could use a cheap microcontroller chip to trigger a relay or SCR, (most accurate, but adds a few dollars to the cost and complicates the design, but if exact timing is needed, its a good solution.)

Currently the machine has one of these in it:

http://babelfish.yahoo.com/translate_url?doit=done&tt=url&intl=1&fr=bf-home&trurl=http%3A%2F%2Fwww.meyer-hartwig.de%2Fde%2Fhome%2Fsv_halbleiter%2Fsv_halbleiter.html&lp=de_en&btnTrUrl=Translate

I dont know how to test it, or verify that it isn't working. This "switching timer" is wired between two contactors that fire 110 volt solenoids in sequence. Problem is, the solenoids dont seem to be switching in squence. If I can figure out a work-around I can at least get this guy's machine up and running.

Any ideas, or do you need more info? I don't think it needs to be "exactly" 100ms, and I'm guessing that this part isn't real expensive, so a cheap way to cause the same thing to happen would be what I'm looking for.

Thanks!

[12oclocker]

the switching timer is defective and needs replaced. that is the simplest solution.

sounds like it is internally shorted it, I've never had to use one of those components before, but after reading the description, this is how it works....

the switching timer resistor is cold, has a very high resistance.

once current is put through it, it starts to heat up, and resistance starts reducing.

after x ms, the part reaches the needed resistance to trigger the device it is in line with.

Thus if your no longer acheving the delay the device once was producing.

These are the 2 possible problems.

1) the device is stuck at trigger temperature (unlikely, unless something is abnormally hot around that part)

2) The part is internally shorted.

To test the part, take it out of the circuit, and take a KNOWN good one out of the circuit. Compare the resistance measurements. They should be within 5% or 10% or 20% of each other. (depending on the manufacturer specified tolerance of the part)

[Todd#43]

the switching timer is defective and needs replaced. that is the simplest solution.

sounds like it is internally shorted it, I've never had to use one of those components before, but after reading the description, this is how it works....

the switching timer resistor is cold, has a very high resistance.

once current is put through it, it starts to heat up, and resistance starts reducing.

after x ms, the part reaches the needed resistance to trigger the device it is in line with.

Thus if your no longer acheving the delay the device once was producing.

These are the 2 possible problems.

1) the device is stuck at trigger temperature (unlikely, unless something is abnormally hot around that part)

2) The part is internally shorted.

To test the part, take it out of the circuit, and take a KNOWN good one out of the circuit. Compare the resistance measurements. They should be within 5% or 10% or 20% of each other. (depending on the manufacturer specified tolerance of the part)

That's how I thought it worked too, based on what it was supposed to do.

Unfortunately, I dont have another one - this is the only one on the panel - to test it against. If I understand you correctly, though, I should be able to see some resistance across it, right?

Anyway, any idea what I can replace this with? Anyone aware of a US Based manufacturer that I can get one from?

Thanks for the help so far - I think I'm on the right track.

[12oclocker]

post up the exact part numbers from the part on here.

[Todd#43]

post up the exact part numbers from the part on here.

The part number is:

SV 100ms/40

Its on a 110v circuit.

[Todd#43]

Ok....little more info from the manufacturer:

>You can test the device with an Ohm-meter. If it is intact resistance would range betweeen 0.5 kOhms and 5 kOhms. The function is to provide a delay in turn on if connected at contactor.

>Let me remark that typ SV 100ms/40 is designed for 220 V mains. It will work on 110 V circuit, but delay time is increased to round about 1 second.

So I tested it yesterday, and I get 6.4 ohms across the leads. I'm assuming that means the part is toast.

The new question is "how do I get a delay of around 1 second across the poles of the contactors?"

[12oclocker]

that can't be the part number, whats the number on the componet? if that is the number stamped on it, then you'll need to lookup replacement parts by punching in the model number of your machine you are repairing in google.

yes, 6.4ohms for that part is toast.

[Todd#43]

that can't be the part number, whats the number on the componet? if that is the number stamped on it, then you'll need to lookup replacement parts by punching in the model number of your machine you are repairing in google.

yes, 6.4ohms for that part is toast.

Yup, that's the part number on the part. This machine is 26 years old, and obviously Meyer-Hartwig has changed their naming convention slightly over the years. There's nothing on the net for this machine either - I looked for that two weeks ago.

I guess I'm going to have to find some way to wire a timer between those two contactors....

[12oclocker]

I doubt its very time sensitive, you could use a RC charge network to switch a transistor which switches a relay.

Or find a similar machine and get another part number for the same kind of part.

[Todd#43]

I doubt its very time sensitive, you could use a RC charge network to switch a transistor which switches a relay.

Huh??