Help Needed With Wiring Mashmate

[pokolbinguy]

G'day folks,

So here's whats happened. I was cutting a suitable hole in the front of my "to-be" control box for my MashMate Controller


And noticed that the plug for the sensor from the controller had come off (the one attached to the two white wires from the controller). So the problem is how do I determine which wire is which as they are both white.... and also I was hoping to replace the plug that is on the cable with some form of socket/plug setup that I can mount on the side of my control box. Something like a head phone jack setup. So i can unplug the cable with ease.

Sooo:

1. How to I work out which wire is which, and

2. Can I use a headphone jack or similar for a replacement plug. If so what should I buy? Maybe use two RCA style plugs similar to a audio setup???

Maybe something like this on the side of my control box?



Thanks for your help folks.

Cheers, Pok

 

[LethalCorpse]

Depends what type of sensor it uses. If it's a resistive sensor, like an NTC thermistor, then it's unpolarised and those wires can go either way. If it's a diode/IC/thermocouple sensor then it can only go around one way, but putting it backwards shouldn't hurt it in any of the cases I can think of. So basically hook it up and see - if it performs as it should, leave it, if it doesn't work, swap it around. It can display the present measured temperature can't it? This will give you a weird reading if it's polarised and you've got it backwards.

Yes, you can use a headphone or RCA socket for connection, but bear in mind that every extra connection will slightly degrade your accuracy.

 

[pokolbinguy]

Depends what type of sensor it uses. If it's a resistive sensor, like an NTC thermistor, then it's unpolarised and those wires can go either way. If it's a diode/IC/thermocouple sensor then it can only go around one way, but putting it backwards shouldn't hurt it in any of the cases I can think of. So basically hook it up and see - if it performs as it should, leave it, if it doesn't work, swap it around. It can display the present measured temperature can't it? This will give you a weird reading if it's polarised and you've got it backwards.

Yes, you can use a headphone or RCA socket for connection, but bear in mind that every extra connection will slightly degrade your accuracy.

Thanks for the help there LC. I will get my hands on a "Stero" headphone plug and sock. That should solve the problem. And that won't put anymore connections in the cable then there is now

And as far as I know it is a NTC sensor.

Cheer, Pok

 

[the egg]

I can confirm that it is a thermistor and the polarity doesn't matter.
It will work either way.

 

[pokolbinguy]

I can confirm that it is a thermistor and the polarity doesn't matter.
It will work either way.

Fantastic. Thanks for the help.

Pok

 

[petesbrew]

If it's just 2 wires, a mono headphone plug would do, no need for the stereo plug.

 

[pokolbinguy]

If it's just 2 wires, a mono headphone plug would do, no need for the stereo plug.

So you can send two signals down a mono plug? Because there will be an "upstream" and "downstrea" signal???? Does that make sense?

Cheers, Pok

 

[LethalCorpse]

So you can send two signals down a mono plug? Because there will be an "upstream" and "downstrea" signal???? Does that make sense?

Cheers, Pok

Not quite. The temperature probe is basically a resistor whose resistance changes proportionally with temperature. The NTC stands for negative temperature coefficient, which means the resistance gets smaller as the temperature gets higher. Since it's basically a resistor, you only need two wires to connect it to the circuit. The way the circuit measures the temperature is, effectively, by measuring the resistance of the thermistor, though it can't do this directly. Either it sends a fixed current through it and reads the voltage produced across it, or it uses the thermistor as part of a voltage divider.

A mono socket provides two connections. The reason you think of it as single channel is because typically you use it to connect a signal path and a ground, which is what you need for a mono connection.

 

[pokolbinguy]

Not quite. The temperature probe is basically a resistor whose resistance changes proportionally with temperature. The NTC stands for negative temperature coefficient, which means the resistance gets smaller as the temperature gets higher. Since it's basically a resistor, you only need two wires to connect it to the circuit. The way the circuit measures the temperature is, effectively, by measuring the resistance of the thermistor, though it can't do this directly. Either it sends a fixed current through it and reads the voltage produced across it, or it uses the thermistor as part of a voltage divider.

A mono socket provides two connections. The reason you think of it as single channel is because typically you use it to connect a signal path and a ground, which is what you need for a mono connection.

So as suggessted above a mono socket will do the job?


So I can use these:

Plug

Socket

Pok

 

[LethalCorpse]

yep, no worries.

 

[petesbrew]

Sorry, POK, forgot all about this post.
Haven't wired a temp controller, but as Lethalcorpse said is correct. Just use a 2 core cable. One wire to the lead & one to the ground.

All down to cost really. (but really we'd probably only be talking a dollar or two right?)
Pete
p.s please correct me if I'm wrong