Originally Posted by Al_The_Man  You did not say what you are inputing the signal to, if you put something like the MicroSwitch unit on, if you put it on the DC side, it won't matter if it is on the high side or ground side, it will operate up to 16vdc supply and will input directly to some low current opto inputs that require a sink input for on. Most are configured this way. It would only require a FET buffer (2n7000) to raise the current drive to 200ma or use it for TTL input or relay driver.
Some systems use this for arc transfer or to constantly monitor the Arc Good condition.
Al. |
I have already attempted to use a reed switch (Hamlin P/N 59145-020 0549) which was unsuccessful. The switch would work for a few seconds and then fail closed. I started out actually using the reed switch that is used inside of the larger Miller machines. This was on the recommendation of a Miller tech rep. I had actually bought the $60 switch direct from miller and found out that its the same switch p/n that I previously mentioned. The switch from Milller comes with a cage around it for the ground lead to go through but its not needed so I just bought the switch itself from digikey. The power supply that runs through the switch is a little transformer from some household item like a small widget light or something.
BTW I am using an MP1000 torch height controller. The current draw through the reed switch from the torch height controller card is very very low so it shouldnt be burning up the switch. The dataplate on the power supply is 9vdc @ 500mA.
I have an online buddy that a plasma cam so he has the instructional video for connecting just about any plasma machine. From the clip that he sent me (relating to the Miller Spectrum 625 and Hobart Airforce 625) it looks like plasma gets its own arc good/xfer from sensing the torch voltage. Is this true?
Does anybody have some pictures of how they connected their miller machine? Thanks, Steve