Electronics > Projects, Designs, and Technical Stuff
Need some help building a circuit involving switchs and relays
<< < (13/14) > >>
Shaydzmi:
I replaced with a 10 \$\Omega\$ resistor, burned out.
Renate:
Ok, then something is wrong here.
A 1/4 W resistor should be able to take a load of 3 lightbulbs no problem
3 * 50 mA = 150 mA
(150 mA)^2 * 10 ohms = 225 mW

With the control board disconnected, measure the resistance from the feeder wires to ground.
Since you know where they are spliced you can measure them individually.
They should both be infinite ohms with all the yarns in place.
Shaydzmi:
I don't think that there is a problem, I think the burn of the resistor is a cause of the fact that here were no yarn in the feeders, so their switches were closed all of them.

What I did after is making a short between the thermistor's legs, and tested 76 bulbs , and after that 152 bulbs, they didn't dim at all, however the triac got little bit hot.
I measured the current when 152 bulb on was around 5 amps.
Renate:
You didn't mention that the yarn was out in half the feeders.

The thermistor might not have a very long life if it often sits there in overcurrent mode.
Why is this machine powered up when half the yarn isn't there?
Does it need to be on when you are setting it up?

This makes a good design a little bit more complicated.
All 168 bulbs at full brightness would be 8.4 Amps.
That represents a combined load of 2.857 ohms!
Throw in those 1.2k bypass resistors and you have an actual load of 2.041 ohms.
Shaydzmi:
I was wrong counting bulbs above, I corrected it.


--- Quote ---You didn't mention that the yarn was out in half the feeders.
--- End quote ---
It was out only when I replaced the thermistor not before.


--- Quote ---The thermistor might not have a very long life if it often sits there in overcurrent mode.
--- End quote ---
Usually ther will be less that 10 bulbs on, but in some cases half of them or even all of them, but this case is rare,for example when a new worker doesn't know what he is doing, or when the belt broke.

--- Quote ---Does it need to be on when you are setting it up?
--- End quote ---
Yes.


--- Quote ---This makes a good design a little bit more complicated.
All 168 bulbs at full brightness would be 8.4 Amps.
That represents a combined load of 2.857 ohms!
Throw in those 1.2k bypass resistors and you have an actual load of 2.041 ohms.
--- End quote ---

The brightness doesn't matter that much when most of the bulbs are on, we need it only when 20 or less are on .
Btw: Other brand machines when 7 are on automatically turned off, and blink once every 5 seconds or so.
Navigation
Message Index
Next page
Previous page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod