relays again
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Posts: 46,084
Hi everyone,
I am on relay number 4, trying to turn on a relay using my serial port and a
BS2 . I have been patterning my relay circuit after those I have seen on
websites I've read about here on this list.
1) Rentron and Shaun Wilson both say "Note: Be sure not to use the stamps
voltage regualtor for powering up the relay coil becuase it can only source
50mA, and one relay would use close to 60mA."
Are they implying that I must build a seperate 5V power supply just to turn
on these stupid coils? I am currently trying all this on a Super Carrier
Board...Is there not an appropriate source of 5V on this board? ( I
thought you should not power it off of the stamp pin itself, but that
elswhere on the board would be ok.
for reference, here are plain text links to the sites Ive been using
http://geocities.com/SiliconValley/Orchard/6633/vbonoff.html
http://rentron.com/pc-relay.htm
Here's what I have currently circuit-wise
(pin 0)
PO
vvv 10k vvv
|
|
|
(B)
( )
( MPS2222A )
( )
| | 120VAC
/ \ o o
(E) (C)
/ \ ______ \
/ \__ ______| relay |___________Vdd
|______|
---
|
>|----|
--
1N4001
-
Like I said Ive tried 4 different relays, so Im curious as to what is
going on.......Ive checked with the meter and I am getting 5V to the
transistor so I assume this is a relay problem.. Can anyone shed some
light on what I might be doing wrong?
Thanks
Dave
I am on relay number 4, trying to turn on a relay using my serial port and a
BS2 . I have been patterning my relay circuit after those I have seen on
websites I've read about here on this list.
1) Rentron and Shaun Wilson both say "Note: Be sure not to use the stamps
voltage regualtor for powering up the relay coil becuase it can only source
50mA, and one relay would use close to 60mA."
Are they implying that I must build a seperate 5V power supply just to turn
on these stupid coils? I am currently trying all this on a Super Carrier
Board...Is there not an appropriate source of 5V on this board? ( I
thought you should not power it off of the stamp pin itself, but that
elswhere on the board would be ok.
for reference, here are plain text links to the sites Ive been using
http://geocities.com/SiliconValley/Orchard/6633/vbonoff.html
http://rentron.com/pc-relay.htm
Here's what I have currently circuit-wise
(pin 0)
PO
vvv 10k vvv
|
|
|
(B)
( )
( MPS2222A )
( )
| | 120VAC
/ \ o o
(E) (C)
/ \ ______ \
/ \__ ______| relay |___________Vdd
|______|
---
|
>|----|
--
1N4001
-
Like I said Ive tried 4 different relays, so Im curious as to what is
going on.......Ive checked with the meter and I am getting 5V to the
transistor so I assume this is a relay problem.. Can anyone shed some
light on what I might be doing wrong?
Thanks
Dave
Comments
plain text.....sorry if this bothers anyone....as far as the "ASCII"
schematic.....well, It looked good before I sent it.. If I need to,
I will post the pic of the circuit somewhere. Let me know.
Dave
>voltage regualtor for powering up the relay coil becuase it can only source
>50mA, and one relay would use close to 60mA."
>
>Are they implying that I must build a seperate 5V power supply just to turn
>on these stupid coils? I am currently trying all this on a Super Carrier
>Board...Is there not an appropriate source of 5V on this board? ( I
>thought you should not power it off of the stamp pin itself, but that
>elswhere on the board would be ok.
The stamp itself has a 5 volt regulator on it. This is what they are
referring to. It is limited in what it can do. I am not familiar with a
Super Carrier board, but I must believe that it also has a 5 volt regulator
on it and *that* one would drive a relay. I couldn't make out your ascii
schematic, but +5 should go to the collector, the emitter to one side of the
relay coil, and the other side of the relay coil goes to ground (Vss). The
base connects to the stamp port through a suitable resistor (your 10k should
be fine). Don't forget to place a diode in parallel with the relay coil
with the banded end toward +5. Make the pin an output and drive it high to
turn on the relay.