Problem- Need some help in electronic connectios

[Rene Nuñez Paz]

Hello

Iam attaching a diagram of connections of my cnc controller…

I need your help in three questions; each question number is relative to the number zone in diagram

1-Need some extra device in transformer-bridge-capacitor zone?

2- I need start DC motor using this Mini relay card, from CN4PC, Is necessary some extra device between LPT Pin1 and DC Relay card.?

3-I need some guide to build a cheap card to manually control speed of DC Motor,,,, (24 Volts - 3Amp.)

Thanks in advance for your help

Regards

Rene

[doorknob]

Originally Posted by Rene Nuñez Paz 1-Need some extra device in transformer-bridge-capacitor zone?

If I am interpreting your diagram correctly, there is a problem with the way that you are planning to hook up the capacitor.

Your diagram shows the capacitor in series between the + output terminal of the bridge rectifier and the + DC output terminal of your power supply. That will not work as expected.

Instead, the capacitor needs to be wired with its - terminal connected to the bridge rectifier's - terminal, and the + output of the power supply must be taken from the junction of the capacitor's + terminal and the bridge rectifier's + terminal.

[Rene Nuñez Paz]

Thanks for your answer
Sorry, my diagram is incorrect, checked connections and + and - wires are coneccted correctly to capacitor, My tranformer is 110-13 volts
and gives me 18.5 VDC in the other side. My question remains about this is if is needed some extra capacitor or electronic device in this zone, for a correct work.

Thanks a lot

Regards

Rene

[john_100]

18.5V is a little low , the hobby cnc boards require a minimum of 24V


the CNC4PC C9 relay board has a opto-isolator input to be controlled by a
+ 5V TTL logic gate output ( as in the original PC printerport )


for the motor speed control try the following links :-

http://www.electronickits.com/kit/co...tor/ck1400.pdf

http://www.velleman.eu/downloads/0/i...k8004_rev3.pdf


John

[Rene Nuñez Paz]

Hello

Thanks for your answer John_100

Sorry, I forgot this about hobby cnc board, My cnc router runs using this card, but using 34 VDC, I should buy one 110-16 (minumun output)

About C9 relay, sorry my requestion, but sometimes its difficult to me a good unsderstanding of technical things in english,
Please answer me this, is more easy for mi understand

May I connect directly PP PIN 1 to PULSE IN connector and Pin 25 to GND connector?

Thanks for links, very useful

Regards

Rene

[doorknob]

Originally Posted by Rene Nuñez Paz May I connect directly PP PIN 1 to PULSE IN connector and Pin 25 to GND connector?

As long as your parallel port can put out a +5 volt signal with sufficient current to light up an LED (perhaps 5 mA or more), it should be OK to hook pin 1 directly to PULSE IN and pin 25 to GND.

To determine that, you can do a test with a multimeter and a resistor with a value in the range of approximately 470 ohms to 1K ohm - with the resistor connected between pin 1 and GND, measure the voltage on pin 1 when that pin is set to a "high" logic level, and if it shows close to +5 volts, then it should work OK.

(Some parallel port cards only put out 3.3 volts, which might not be sufficient. Also, some parallel port cards may put out 5 volts, but they may not be capable of sourcing enough current to drive an LED.)

One thing to think about - when you power up your PC, before you run your CNC control software, is it possible that your parallel port will put out +5 volts on pin 1 when you are not expecting it? If so, that could cause unexpected activation of your motor, which could be a safety problem.

[Rene Nuñez Paz]

Hello

Perfect, Now I understood perfectly,

My parallel port is from MB, also I have and external PCI Card.
I have a led from an old printer wired, I will do the test
If not work try then second test using millimeter.
If not is enough current, How can I do the connection for relay?

In my software the signal for activate dc motor is coming out from each output pins, I can select one only,,

Now,,,about unexpected 5VDC in PIN1 in power up PC..
DC motor will move needle for a embroidery machine,, and one needle getting inside a finger is not very nice!!!

What solutions take??

1-Power on DC Motor transformer, after power on PC, but sometimes this can be forgetter. I think is not a good idea

2- Please, I don’t have other ideas….

Thanks in advance

Rene

[doorknob]

If your parallel port does not output sufficient current, you can use a "buffer board" to increase the current.

See CNC4PC C26 - OUTPUT BUFFER BOARD

As far as handling possibly unexpected 5VDC on PIN1 when powering up the PC, will you be using Mach3 software? If so, Mach3 supports a "charge pump circuit" that is designed to prevent activation of a CNC machine unless Mach3 is in control.

See CNC4PC C4- Safety Charge Pump