Ron,
As previously stated in reply to Sgt Wookie's question......

"I see you're using a 12v supply. Is this thing going to be installed on a boat/car, or is this just an experiment with PSPICE?


My reply was.....

(working with the "12v Counter kit" I have)
"an "Equal out" pin (wire) that offers 5V @50ma when the count reaches a preset number (default=0000). One can preset any number into it, then begin the count, and upon reaching that preset number the pin/wire exhibits 5V @50ma, and that is the only way one can make the thing auto-stop counting, even on zero (actually, am going to use a couple more relays activated by the begin auto count buttons, (relay current values changed). See attached Pic
So, I had ordered some little 5V 20ma relays (just came in this afternoon)
and, yesterday decided to try and design a switching transistor to operate a relay I happened to have on hand (5V@89.3ma), and also decided to play around with the simulation program, thus winding up here on the forum, etc...."
See attached Pic--> K1 is this relay ! ! !

This Switching transistor/w/relay was/is a learning experience for me to know how to do it, etc....
Had I not recieved my 5v@20ma relays I would've used the design we just created.....

I used an 82 ohm resistor (1/4w) but it measured 80.5 ohms on my meter.
Yes, it got hot, figured it's pwr, supposed to be a little over .5W, will use a 1W if I ever build it for real, etc.....

Sarge,
Going lower in ohms (75 ohms) would probably work, but wouldn't I rather go higher to keep Ic lower=less pwr, and it would still work ?
Will copy all your info concerning the simulator, etc.
OK, got your attachment.....

 

Resistor power:
R2 dissipates approximately 600mW when Q1 is conducting. So, 600mW x 2 = 1.2 Watts. You need to use a resistor that is rated for at least 1.2W. Since they don't make 1.2 Watt resistors, you'll need to go up to the next higher value, which is 2 Watts.

Alternatively, you could use a pair of 160 Ohm 1W resistors in parallel to get 80 Ohms, or a 39 Ohm 1W in series with a 42 Ohm 1W to get 82 Ohms.

Either 75 Ohms or 82 Ohms will be fine. The important thing is to use a resistor with a power rating that's high enough.

Something you need to be aware of when using switches and relays is "contact bounce". PSPICE simulators don't show this phenomenon. When "real-world" switch or relay contacts open and close, it is not instantaneous; they may open and close many times before reaching a steady state. You need to be aware of this, because otherwise you can wind up having very odd problems that are tough to solve.

Here is a link to a PDF document written by Jack Ganssle about contact bounce and various ways to de-bounce switch/relay contacts: http://www.ganssle.com/debouncing.pdf
It's well worth reading through a few times.

 

Sarge;
10-4 on the 2-watts....And other info.....
Played with your .CKT simulation.
Changed my settings (Analysis Setup).
Problem= My O-Scope disappears when I click on something.
Should be simple, please advise......

 

Problem= My O-Scope disappears when I click on something.
Should be simple, please advise......

On the Menu Bar, click "Window", then "Tile Windows"
You should then be able to see both your schematic and the O-scope.

If the circuit is too large to fit, on the menu bar click "View", then "Fit Circuit to Window" - or press F4.

 

10-4, got it...
Tx's so much.
Am moving on to bread-boarding my relay board.....
Tx's so much everybody...
Oxbo