BOB to Solid State Relay Plasma CNC wiring

I have the SSR and breakout board pictured. Currently I have it wired as follows.
pin 3+ of SSR to 5v+ on breakout (Verified 5 volts with DVM)
Pin 4- of SSR to to output 1 of Breakout.

Pins 1 and 2 of the SSR I have yet to figure out how they wire to the torch.

When I run Mach 3 on a test bracket I made in Sheetcam, the SSR doesnt do anything. The red light just stays lit all the time. I used Diagnostics in Mach 3 to manually turn on/off spindle controll and no changes. All i get is Mach says output one is active and output one blinks on the screen when I turn it on. I plan to hook this up to a Thermal Dynamics cutmaster 52.

I'm wondering if anyone knows how to wire this up, because I don't think I did it correctly.

if the mach 3 is setup correctly for your printer port
I would of expected the relays LED indicator to switch on and off as mach 3 switches the spindle control on and off

one possible problem may be your printer port only switches between 0V and 3V and not 0V and 5V as the original IBM printer ports did

connect your voltmeter across the relay input terminals (pins 3 & 4)
when the printer port pin is at logic 0 the pin will be at 0v and you will measure 5V at the relay input

when the printer port switches to logic 1 the pin ideally should be between +4 or +5V so the voltage at the relay input will be 1V or less
(+5V supply on relay terminal 3 less the positive voltage from the printer port pin 1 connected to relay terminal 4)

you may find if the printer port pin is at +3V so the relay input is 2V that its enough to switch on the relay even though its less than the 3-32V stated on the relays label

John

Im pretty sure mach 3 is set up correctly, but if not do you have a quick rundown of the ports and pins, and spindle settings.

What options do I have if I my printer port is only 0-3volts? Im running a 04' dell desktop.

I just measured 2.44 volts across pins 3-4. How do i get more volts? To power the relay correctly?

Correction, i get 4.37volts across 3 and 4 of the relay. i measured the first time without the computer on.

when you switch the relay in mach 3

whats the second voltage reading across the relay input ?

if the two voltages are 0V and +2.44V
you could try connecting
relay terminal 4 to the printerport ground and the
relay terminal 3 to the printerport pin 1


if 2.44V proves not to be enough to switch the relay on
the only option is to use a transistor or other device as a buffer between the printerport and the relay

John

now you corrected the voltage measured to 4.37V
that will be when the printer port pin 1 is at 0.63v ( logic 0) to switch the relay will be ON

what do you measure when mach 3 switches pin 1 to logic 1 ? to switch the relay OFF

Sorry my actual voltage with computer on, and mach running and everything plugged in is 4.37volts, i originally measured with the computer off and just the breakout board and the drivers plugged in.

Voltage is the same, when im in diagnotic in mach 3 turning spindle control on or off. The Light says pin 1 active and then pin 1 on the screen flashes but the voltage stays the same, accross 3-4 of the relay. The light on the solid state relay is on also

Looking like i might not have the mach3 settings correct?

Heres some screen shots of my settings in Mach3, If you wouldn't mind taking a look.

Personally I would buffer the P.P. with a 2n7000, a search here using 2n7000 will bring up many examples, you could still use your 5v supply from the P.C. instead of the 24v some posts show.
http://www.cnczone.com/forums/genera...f_control.html
Al.

after looking at the pictures in the first post again

it looks like the black wire connects the breakout boards ground to the relay negative input pin 4
and the red wire connects the B.O.B's terminal 1 , which is printer port pin 1,
to the relay positive input pin 3

in the second picture in post 8
output 1 port1 is assigned to printer port pin 16 - change this to pin 1

this should now work if the port can supply the 3 or 4 mA the relay requires


better still , assuming the 5V supply for the breakout board is taken from the PC USB port,
connect the relay positive input terminal 3 to the +5V terminal on the breakout board


connect the relay negative terminal 4 to the printer port pin 16 (as assigned in picture 2 post 8)
- note this pin will now need to be active low !


( the printer port pins can sink more current to ground than source
current from the 5V supply )

John

do you have a link to the instructions for the breakout board ?

Thanks you so much John100. It worked after I changed the pin as you suggested and swapped the black and red wires. Now when I have the spindle toggled off, the light on the SSR is off., and when I toggle it on the Light on the SSR is on.

.08 volts when toggled off across pin 3,4
3.07 volts when I toggle it on across 3,4

Now whether it works when I attach it to my Thermal Dynamics 52 will be a whole nother story. Im assuming it should. At some point I think im going to updgrade to some gheckos G203v's or the 201x.

try this circuit, last time i use for control torch my plasma .