Driver Help

[jordan]

Ok, so i was able to make a SSR and build it into a box, all the connections are fine, i tested them.
the main problem is that when i connect it to the computer, all the LEDs come on (currently 3 but I'm trying to make more) when i start vixen, i am not sure what drivers i need to use. here is the circuit diagram
http://users.on.net/~driver/lights/images/control/SSR.gif

are there any ideas into the driver i can use

Thanks
-Jordan

[shocker]

you need an interface like renard,grinch,etc...

[jordan]

what exactly is that?

[jordan]

and where can i find them?

[Wayne J]

Here, of course. :)

First off, how many of these ssrs do (will) you have? If they all will be a single channel design, you can use a parallel port control.

[jordan]

this year only 5-8 channels right now, i just finished the 4th

[jordan]

and yes single channel per ssr

[pete]

Jordan, sounds like what you want to do is a 8 or 12 channel setup directly off your parallel port. Here is the pin assignment to run up to 12 channels off a parallel port, just in case you feel like making up 4 more SSRs. In vixen you would uses either the basic parallel plug-in for up to 8 channels or the 12-channel plug in for the 12 channel setup. You can modify an old printer cable if you have a meter to ring out the wires or make up you own. the DB25 connectors are available at radio shack. Any question on this you can PM me or caught me in the chatroom.


Good Luck,

Pete

[JetMech]

The MOC3021 is a 15mA part where the MOC3023 is a 5mA part. The typical forward voltage is 1.15v with a max of 1.5v.
Using the 300 Ohm resistor in your circuit implies a parallel port 'high' pin voltage of 5.65 to 6 volts to fire reliably. Your Parallel Port most likely won't be that high. I don't know how much current the port can supply but I doubt it will enough for both the opto and LED, you could overload the port and damage your computer.

You could try using a ULN2803 for 8 channels as in this how to:
http://computerchristmas.com/christmas/link-how_to/HowToId-17/Control_using_a_ULN2803A

John

[jordan]

John,
The parallel on the computer I'm using supplies 4.56 volt on average, when the port is switched off it puts out 0.18 volts.

And I forgot to mention that I have changed some of the parts to fit my needs. the resistor that goes to the LED has been changed to 300 ohm rather that 150 and the parts that changed are:
7X MOC3021--->1X NTE3048
7X BT137F------> 1X NTE5609

the store ran out of the MOC3021 and BT137F so i used NTE equivalents for the last channel
if necessary I can link to the the product spec sheet.



Thanks
-Jordan

[JetMech]

I am no expert when it comes to electronics, but I have read and learned a lot in the last couple of years in this 'new' hobby. One is that there are no guarantees. The parallel port was designed for printers, not driving LED's, their capabilities vary greatly from computer to computer. Google "parallel port current output" and you will find about 2,300,000 English pages for your reading pleasure. Here is an excerpt form just one.

http://www.epanorama.net/circuits/parallel_output.html


The outputs are designed so that they give at least 2.4V at 2.6 mA load. This 2.6 mA figure is for ordinary LS-TLL circuits used, the LSI implementations used in many computers can give more or less. For example quite popular (few years ago) UM82C11-C parallel port chip can only source 2 mA.

The NTE3048 is also a max 15mA part (with 8mA typical).
From the Datasheet:

Note 4. The NTE3048 is guaranteed to trigger at an IF value less than or equal to max IFT. Therefore,
recommended operating IF lies between max IFT (15mA) and absolute max IF (60mA).

John

Edit: Yet another reference
http://www.beyondlogic.org/spp/parallel.htm

The output of the Parallel Port is normally TTL logic levels. The voltage levels are the easy part. The current you can sink and source varies from port to port. Most Parallel Ports implemented in ASIC, can sink and source around 12mA. However these are just some of the figures taken from Data sheets, Sink/Source 6mA, Source 12mA/Sink 20mA, Sink 16mA/Source 4mA, Sink/Source 12mA. As you can see they vary quite a bit. The best bet is to use a buffer, so the least current is drawn from the Parallel Port.

[jordan]

thank you all for your help, i have managed to get 8 channels up and running.