control the electrical appliances using PC

[ryadav]

Hi,

I used the Circuit Diagram mentioned in the below link to "control the
electrical appliances using PC". But it does not work. Did any one
worked recently on this, if yes does it works?

http://www.ibiblio.org/pub/Linux/docs/HOWTO/Home-Electrical-Control

I used the following components

1. 6 VDC Relay
2. C2235 NPN transistor
3. 1N4007 diode
4. 4.7 K resisitor
5. LED

Only LED glows when parallel port passes +5v. As it is metioned in the
link relays switches
when parallel port passes +5v which is not happening in my case. Please
help me in fixing issue. Relay switch is happening in before parallel
port passes +5v.

 

[ryadav]

what is the wrong in the circuit? why it does not work?


| Vcc for Relay

|

|

/ -------+--------| |---------|

P data 4.7K B / c | 1N4002 |_|
|-------
-----------/\/\/\/\---------+-----| NPN _____ | relay |home
device
| \ e /_\ |-|
|-------
LED X \ +--------| |---------|

P Ground | | |

----------------------------+-------+--------+

Relay Ground |

---------------------------------------------+

 

[ryadav]

Relay will be always glows since diagram shows relay VCC is passed to
cathod end of diode and relay ground given to anode end of
diode. should it be like that?

 

[cbm5]

Hi,

I used the Circuit Diagram mentioned in the below link to "control the
electrical appliances using PC". But it does not work. Did any one
worked recently on this, if yes does it works?

http://www.ibiblio.org/pub/Linux/docs/HOWTO/Home-Electrical-Control

I used the following components

1. 6 VDC Relay
2. C2235 NPN transistor
3. 1N4007 diode
4. 4.7 K resisitor
5. LED

Only LED glows when parallel port passes +5v. As it is metioned in the
link relays switches
when parallel port passes +5v which is not happening in my case. Please
help me in fixing issue. Relay switch is happening in before parallel
port passes +5v.

The circuit is wrong, use the one from
http://www.epanorama.net/circuits/parallel_output.html#relaycontrol

 

[Pooh Bear]

what is the wrong in the circuit? why it does not work?

That circuit is defective.

The base-emitter junction forward voltage should never exceed about 0.7V.
That's not enough to light the LED which is therefore spurious. You say the
LED lights which suggests that you miswired the transistor.

Graham

 

[Pooh Bear]

Relay will be always glows since diagram shows relay VCC is passed to
cathod end of diode and relay ground given to anode end of
diode. should it be like that?

The diode is there to 'catch' the flyback pulse when the relay switches
off ( inductive parts have stored energy ). It's shown connected
correctly.

Graham

 

[Pooh Bear]

Hi,

I used the Circuit Diagram mentioned in the below link to "control the
electrical appliances using PC". But it does not work. Did any one
worked recently on this, if yes does it works?

cbm5 is correct.

The circuit you posted is wrong. The relay should be in series with the
transistor not in parallel. Use the link he supplied.

Graham

 

[Jasen Betts]

Hi,

I used the Circuit Diagram mentioned in the below link to "control the
electrical appliances using PC". But it does not work. Did any one
worked recently on this, if yes does it works?

http://www.ibiblio.org/pub/Linux/docs/HOWTO/Home-Electrical-Control

I used the following components

1. 6 VDC Relay
2. C2235 NPN transistor
3. 1N4007 diode
4. 4.7 K resisitor
5. LED

Only LED glows when parallel port passes +5v. As it is metioned in the
link relays switches
when parallel port passes +5v which is not happening in my case. Please
help me in fixing issue. Relay switch is happening in before parallel
port passes +5v.

it needs extra power for the relay. pin 1 of the joystick socket has 5V
which might be anough, otherwise use a 6V plugpack.

Bye.
Jasen

 

[Jasen Betts]

Hi,

I used the Circuit Diagram mentioned in the below link to "control the
electrical appliances using PC". But it does not work. Did any one
worked recently on this, if yes does it works?

http://www.ibiblio.org/pub/Linux/docs/HOWTO/Home-Electrical-Control

that circuit in that document is bullshit, try the coffee howto instead

http://www.ibiblio.org/pub/Linux/docs/HOWTO/Coffee.html

It gives this circuit which is very conventional.
you ca probably make it work with the parts you have.


Vcc
|
+------+
| __|__
Relay /^\ Diode 1N4002
Coil /---\
| |
+------+
|
| /
4.7K B |/ C
parallel port >-\/\/\/\/---| NPN Transistor: BC547A or 2N2222A
data pi |\ E
| \
V
parallel port >--------------+
ground pin |


I'm submitting a bug report on the Home-Electrical-Control document.

Bye.
Jasen

 

[Bob Masta]

Hi,

I used the Circuit Diagram mentioned in the below link to "control the
electrical appliances using PC". But it does not work. Did any one
worked recently on this, if yes does it works?

In addition to what others have posted, note that NT-based
versions of Windows (NT, XP, 2000) don't allow direct access
to the ports, so you will probably need a special ring 0 driver like
GIVEIO for them. That won't be needed for Win9x and earlier.

Best regards,


Bob Masta
dqatechATdaqartaDOTcom

D A Q A R T A
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Home of DaqGen, the FREEWARE signal generator

 

[ryadav]

In addition to what others have posted, note that NT-based
versions of Windows (NT, XP, 2000) don't allow direct access
to the ports, so you will probably need a special ring 0 driver like
GIVEIO for them. That won't be needed for Win9x and earlier.

Best regards,


Bob Masta
dqatechATdaqartaDOTcom

D A Q A R T A
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Home of DaqGen, the FREEWARE signal generator

Thank you all, finally it worked with new circuit provided in the URL
posted.

 

[Big Mouth Billy Bass]

what is the wrong in the circuit? why it does not work?

Quite a bit seems to be wrong. The thing that catches my attention is
that, as drawn, the relay will always be "on," regardless of the state
of the applied data. You've got "Vcc" and "Relay Ground" hard-wired
across the relay.

 

[Jasen Betts]

Quite a bit seems to be wrong. The thing that catches my attention is
that, as drawn, the relay will always be "on," regardless of the state
of the applied data. You've got "Vcc" and "Relay Ground" hard-wired
across the relay.

if the power supply for the relay is short-circuit protected and rather wimpy
and the NPN has enough gain. it could work by the NPN shorting out the
supply and turning the relay off.

if not the best you can hope of is for it to fail in an unspectacular way.

Bye.
Jasen