Input / Output
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Hello,
I have a question. I need to control 64 relays (250 VAC, 25 Amp) with the
Basic Stamp. Is this doable ? How do I go about getting started ?
Thanks alot,
Steve Gillem
I have a question. I need to control 64 relays (250 VAC, 25 Amp) with the
Basic Stamp. Is this doable ? How do I go about getting started ?
Thanks alot,
Steve Gillem
Comments
>Hello,
>
>I have a question. I need to control 64 relays (250 VAC, 25 Amp) with the
>Basic Stamp. Is this doable ? How do I go about getting started ?
>
>Thanks alot,
>
>Steve Gillem
Steve -
You may want to look at some of the driver chips offered by Allegro Micro.
Here is the web page with many of their drivers, some of which offer 32
drivers on one serially operated IC:
http://www.allegromicro.com/selguide/ipid1.asp
Hope that gets you started.
Regards,
Bruce Bates
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www.al-williams.com/awce. You then use as many PAKIII's as needed, with each
PAKIII's I/O pin tied to a relay driver. This would give you complete
individual control of each relay.
The next method is to use a shift register, such as those found at
www.allegromicro.com IC's like the 10bit 5810, or 5818 32 bit driver would
work good. These chips are serial in parallel out. What you do to use shift
register like devices is to disable the output of the IC, then clock in
serially which bits (or ports) you want on or off, and then enable the
output and the relays would be activated as programmed. If the relays were
little, you might be able to control them directly, but the current has to
be less than 25ma per coil. You can cascade the shift registers or run them
on their own separate I/O pins.
Most an other shift register would work as well too.
Assuming DC coil powered relays....
One way is to use a small reed relay to drive the larger relay, some of the
small reed relays can be driven directly as they need less than 25ma to
power the little coil in them. Then the reed relay runs the larger relay.
Small relays would use a simple 2n2222 transistor driver to control the
relay coil. A ULN2003 darlington driver might work if the current draw isn't
more than all four driver channels can handle. You can also drive a TIP120
or TIP125 darlington driver transistor(s) to control larger relays, these
transistors can handle a couple of amps OK. Don't forget to use a Schottkey
diode across each coil to help protect the transistors from the reverse
coiul voltage when you turn a relay on or off.
I would suggest using a optoisolator for each relay driver circuit in order
to protect the MCU and stuff from the AC in case a problem occurs (like a
lighning strike or a wiring mistake or a circuit failure and short).
You could also use solid state relays which use triacs or SCR's, but this
starts to get complicated real fast.
Now if your using AC coil powered relays, then you have to start looking at
maybe using SCR's or triacs, although a simple method would be to use a
small reed relay to control and drive the AC voltage going to the larger AC
powered relay. In this case the small reed relays could be driven directly
if the current is less than 25ma. or you could use a ULN2003 driver or
simple 2n2222 transistors.
Original Message
From: sgillem@a... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=h5R0pNbeLhadYBhGqAZtteMFP0COujXDYH5AQ00GzaycT_S_FbG5WeZWaRgA1pTbkMgpgUxhjQ]sgillem@a...[/url
Sent: Monday, May 27, 2002 8:26 AM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] Input / Output
Hello,
I have a question. I need to control 64 relays (250 VAC, 25 Amp) with the
Basic Stamp. Is this doable ? How do I go about getting started ?
Thanks alot,
Steve Gillem
To UNSUBSCRIBE, just send mail to:
basicstamps-unsubscribe@yahoogroups.com
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Body of the message will be ignored.
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many outputs. If you want a single chip solution, consider this.
Our programmable logic tutorial uses a Xilinx 9578 programmable logic
chip to make a "super" output chip that has 32 outputs from a Stamp
using two wires. This takes up about half the chip. See
http://www.al-williams.com/pictutor and click on Xilinx tutorial.
This idea can be expanded by cutting making a copy of the 32-bit output
section and cutting the copy in half (48 outputs). Any more won't fit on
a 9578. You could probably squeeze at least 64 bits on 95108.
This is a sneak preview of the project of the month for June. If there
were enough interest I'd consider making the pre programmed chips
available. Then you wouldn't need the whole kit, just a bare board, a
PLCC socket, and the chip (or just the chip if you are comfortable
working with PLCCs). The details on the kits are at
http://www.al-williams.com/awce/pbx84.htm.
Of course, the great advantage to these is that -- if you know how --
you can add other functions as well (subject to space). So if you need
16 outputs, 10 inputs, and 3 PWM, you could do that. But if on another
project you need 5 PWM, 16 inputs, and no outputs (plus you want the
inputs to latch and provide a single output to show change) you could do
that too. Great fun! You'll read more about it in the June project.
Anyway, just a thought.
Al Williams
AWC
* Floating point A/D
http://www.al-williams.com/awce/pak9.htm
>
Original Message
> From: Earl Bollinger [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=0cu6zwtaKQLZj84IDLOJIkxA-6R3Ph4VgpzJSpHoaQx9y2MN_b-5bE4m1m1_oz365S9fhyrGXaUitHLgFBtVoQ]earlwbollinger@a...[/url
> Sent: Monday, May 27, 2002 8:52 AM
> To: basicstamps@yahoogroups.com
> Subject: RE: [noparse][[/noparse]basicstamps] Input / Output
>
>
> One way is to use I/O expander IC's such as the PAKIII or IV
> from www.al-williams.com/awce. You then use as many PAKIII's
> as needed, with each PAKIII's I/O pin tied to a relay driver.
> This would give you complete individual control of each
> relay. The next method is to use a shift register, such as
> those found at www.allegromicro.com IC's like the 10bit 5810,
> or 5818 32 bit driver would work good. These chips are serial
> in parallel out. What you do to use shift register like
> devices is to disable the output of the IC, then clock in
> serially which bits (or ports) you want on or off, and then
> enable the output and the relays would be activated as
> programmed. If the relays were little, you might be able to
> control them directly, but the current has to be less than
> 25ma per coil. You can cascade the shift registers or run
> them on their own separate I/O pins. Most an other shift
> register would work as well too.
>
> Assuming DC coil powered relays....
> One way is to use a small reed relay to drive the larger
> relay, some of the small reed relays can be driven directly
> as they need less than 25ma to power the little coil in them.
> Then the reed relay runs the larger relay. Small relays would
> use a simple 2n2222 transistor driver to control the relay
> coil. A ULN2003 darlington driver might work if the current
> draw isn't more than all four driver channels can handle. You
> can also drive a TIP120 or TIP125 darlington driver
> transistor(s) to control larger relays, these transistors can
> handle a couple of amps OK. Don't forget to use a Schottkey
> diode across each coil to help protect the transistors from
> the reverse coiul voltage when you turn a relay on or off. I
> would suggest using a optoisolator for each relay driver
> circuit in order to protect the MCU and stuff from the AC in
> case a problem occurs (like a lighning strike or a wiring
> mistake or a circuit failure and short). You could also use
> solid state relays which use triacs or SCR's, but this starts
> to get complicated real fast.
>
> Now if your using AC coil powered relays, then you have to
> start looking at maybe using SCR's or triacs, although a
> simple method would be to use a small reed relay to control
> and drive the AC voltage going to the larger AC powered
> relay. In this case the small reed relays could be driven
> directly if the current is less than 25ma. or you could use a
> ULN2003 driver or simple 2n2222 transistors.
>
>
>
>
Original Message
> From: sgillem@a... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=ryoFsDxSjvLt6PmiMwH5h_3Y2ivKz3keyF8UDtG5oBnfv3YKVQUrb7JNnzP0du0UnPr_D1d4l-0iRw]sgillem@a...[/url
> Sent: Monday, May 27, 2002 8:26 AM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] Input / Output
>
>
> Hello,
>
> I have a question. I need to control 64 relays (250 VAC, 25
> Amp) with the
> Basic Stamp. Is this doable ? How do I go about getting started ?
>
> Thanks alot,
>
> Steve Gillem
>
> To UNSUBSCRIBE, just send mail to:
> basicstamps-unsubscribe@yahoogroups.com
> from the same email address that you subscribed. Text in the
> Subject and Body of the message will be ignored.
>
>
> Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
To UNSUBSCRIBE, just send mail to:
basicstamps-unsubscribe@yahoogroups.com
from the same email address that you subscribed. Text in the Subject
and Body of the message will be ignored.
Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/