a/c coil transient suppression
Archiver
Posts: 46,084
Hi folks,
I'm new to the group and to stamps, so thanks in advance.
Here's the situation: I've got a bs2 controlling a 5vdc relay which switches
a 24vac sprinkler valve controller. The power supply for the whole setup is
a 24vac transformer; I'm using a bridge and regulator to cut it down to 5vdc
for the electronics (with lots of filter caps) and it also powers the valve
selenoid directly via the relay. I've got a rectifier across the relay coil
to clamp spikes, but I have a feeling I need something across the selenoid
(something called a snubber, perhaps?) to block spikes generated by it
during switching. The system behaves somewhat irratically when the selenoid
is switched on and off (scope -- set for a/c, 2v/div -- seems to show
occasional spikes during the switching), it behaves fine without the
selenoid, and also with the selenoid if I put a cap across it (probably not
a great idea since it's driven by a/c).
I'm not that familiar with a/c circuit transient suppression, and would
appreciate any insights.
thanks,
d...
**************************************************************************
* David Okagaki dokagaki@w...
*
* "The light at the end of the tunnel is that of the on coming train!"
*
**************************************************************************
I'm new to the group and to stamps, so thanks in advance.
Here's the situation: I've got a bs2 controlling a 5vdc relay which switches
a 24vac sprinkler valve controller. The power supply for the whole setup is
a 24vac transformer; I'm using a bridge and regulator to cut it down to 5vdc
for the electronics (with lots of filter caps) and it also powers the valve
selenoid directly via the relay. I've got a rectifier across the relay coil
to clamp spikes, but I have a feeling I need something across the selenoid
(something called a snubber, perhaps?) to block spikes generated by it
during switching. The system behaves somewhat irratically when the selenoid
is switched on and off (scope -- set for a/c, 2v/div -- seems to show
occasional spikes during the switching), it behaves fine without the
selenoid, and also with the selenoid if I put a cap across it (probably not
a great idea since it's driven by a/c).
I'm not that familiar with a/c circuit transient suppression, and would
appreciate any insights.
thanks,
d...
**************************************************************************
* David Okagaki dokagaki@w...
*
* "The light at the end of the tunnel is that of the on coming train!"
*
**************************************************************************
Comments
a relay.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2519525232&category=4660
Original Message
From: Dave [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=h2HCuSmPcRsLm8vBu2tnmg70CTzTEx9Vk41tejuVTr9zPech6kWNIaQSipYh_ugGsB6-4GdYpHyjqXdvbEjHtnbg]dokagaki@w...[/url
Sent: Friday, April 04, 2003 12:53 AM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] a/c coil transient suppression
Hi folks,
I'm new to the group and to stamps, so thanks in advance.
Here's the situation: I've got a bs2 controlling a 5vdc relay which switches
a 24vac sprinkler valve controller. The power supply for the whole setup is
a 24vac transformer; I'm using a bridge and regulator to cut it down to 5vdc
for the electronics (with lots of filter caps) and it also powers the valve
selenoid directly via the relay. I've got a rectifier across the relay coil
to clamp spikes, but I have a feeling I need something across the selenoid
(something called a snubber, perhaps?) to block spikes generated by it
during switching. The system behaves somewhat irratically when the selenoid
is switched on and off (scope -- set for a/c, 2v/div -- seems to show
occasional spikes during the switching), it behaves fine without the
selenoid, and also with the selenoid if I put a cap across it (probably not
a great idea since it's driven by a/c).
I'm not that familiar with a/c circuit transient suppression, and would
appreciate any insights.
thanks,
d...
**************************************************************************
* David Okagaki dokagaki@w...
*
* "The light at the end of the tunnel is that of the on coming train!"
*
**************************************************************************
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/
When you wish to suppress noise or switching transients with AC solenoids,
the best devices I have found are the Panasonic ZNR transient/surge
absorbers. Mount one across the solenoid. You must select the proper one
based on applied voltage and application. Check out digikey.com for
information. If you want to use relay switching, just control a standard
relay which will handle the current at the ac voltage you are using with a
transistor switch. Use the ZNR suppressors across the solenoid coil and a
diode across the relay coil to suppress switching transients or you could
switch a solid state ac relay such as a crydom D1210 (for 120vac @ 10 amps)
or crydom d2410 (for 240vac @ 10 amps). The crydom relays require 3 to 32
volts dc to switch. I recommend using a transistor switch between the stamp
and the crydom relays.
For control configurations using a stamp and transistor switching, check my
web site.
Jim
http://www.geocities.com/jimforkin2003
Original Message
From: James R. Parish [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=uO2Gh1kYkdFlDl6IhPSY6Sg3pZTkoYFGTZBTDyHwikEmdVCK5qij6RXABUUfJl5hSv2pDbGdeLeN-1omvYhq5Q]JamesParish@J...[/url
Sent: Friday, April 04, 2003 7:20 AM
To: basicstamps@yahoogroups.com
Subject: RE: [noparse][[/noparse]basicstamps] a/c coil transient suppression
I would use a CRYDOM solid state relay with ZERO CROSS switching instead of
a relay.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2519525232&category=4660
Original Message
From: Dave [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=hVc_SEPt6yv254A0sgKJWzOfOyB-g2NDWuUAmVT1noTztO_gDYruWJPD1Egq05C8xil5lXjx3J6U_Ig1B_JN5xM]dokagaki@w...[/url
Sent: Friday, April 04, 2003 12:53 AM
To: basicstamps@yahoogroups.com
Subject: [noparse][[/noparse]basicstamps] a/c coil transient suppression
Hi folks,
I'm new to the group and to stamps, so thanks in advance.
Here's the situation: I've got a bs2 controlling a 5vdc relay which switches
a 24vac sprinkler valve controller. The power supply for the whole setup is
a 24vac transformer; I'm using a bridge and regulator to cut it down to 5vdc
for the electronics (with lots of filter caps) and it also powers the valve
selenoid directly via the relay. I've got a rectifier across the relay coil
to clamp spikes, but I have a feeling I need something across the selenoid
(something called a snubber, perhaps?) to block spikes generated by it
during switching. The system behaves somewhat irratically when the selenoid
is switched on and off (scope -- set for a/c, 2v/div -- seems to show
occasional spikes during the switching), it behaves fine without the
selenoid, and also with the selenoid if I put a cap across it (probably not
a great idea since it's driven by a/c).
I'm not that familiar with a/c circuit transient suppression, and would
appreciate any insights.
thanks,
d...
**************************************************************************
* David Okagaki dokagaki@w...
*
* "The light at the end of the tunnel is that of the on coming train!"
*
**************************************************************************
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/
some with up to 20v in with a regulated 5v out most
of these are a switching type were the output is
totaly isolated from the input should take care of any
noise problems from the valve coil
--- Dave <dokagaki@w...> wrote:
> Hi folks,
>
> I'm new to the group and to stamps, so thanks in
> advance.
>
> Here's the situation: I've got a bs2 controlling a
> 5vdc relay which switches
> a 24vac sprinkler valve controller. The power
> supply for the whole setup is
> a 24vac transformer; I'm using a bridge and
> regulator to cut it down to 5vdc
> for the electronics (with lots of filter caps) and
> it also powers the valve
> selenoid directly via the relay. I've got a
> rectifier across the relay coil
> to clamp spikes, but I have a feeling I need
> something across the selenoid
> (something called a snubber, perhaps?) to block
> spikes generated by it
> during switching. The system behaves somewhat
> irratically when the selenoid
> is switched on and off (scope -- set for a/c, 2v/div
> -- seems to show
> occasional spikes during the switching), it behaves
> fine without the
> selenoid, and also with the selenoid if I put a cap
> across it (probably not
> a great idea since it's driven by a/c).
>
> I'm not that familiar with a/c circuit transient
> suppression, and would
> appreciate any insights.
>
> thanks,
>
>
> d...
>
>
**************************************************************************
> * David Okagaki
> dokagaki@w...
> *
> * "The light at the end of the tunnel is that of the
> on coming train!"
> *
>
**************************************************************************
>
>
> 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/
>
>
__________________________________________________
Do you Yahoo!?
Yahoo! Tax Center - File online, calculators, forms, and more
http://tax.yahoo.com
across the selenoid. seems to work great along with the extra filtering.
thanks to everyone who replied!
d...
>
Original Message
> From: Jim Forkin [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=e6lLFSv1uC9o9p3baTS0zxGnS3ETkl99ZzSoX1Q_Qxdr62tpVL7pU3hxnNEMrBlzVBJv66fH19IM]jjf@p...[/url
> Sent: Friday, April 04, 2003 6:17 AM
> To: basicstamps@yahoogroups.com
> Subject: RE: [noparse][[/noparse]basicstamps] a/c coil transient suppression
>
>
> Dave,
>
> When you wish to suppress noise or switching transients with AC solenoids,
> the best devices I have found are the Panasonic ZNR transient/surge
> absorbers. Mount one across the solenoid. You must select the proper one
> based on applied voltage and application. Check out digikey.com for
> information. If you want to use relay switching, just control a standard
> relay which will handle the current at the ac voltage you are using with a
> transistor switch. Use the ZNR suppressors across the solenoid coil and a
> diode across the relay coil to suppress switching transients or you could
> switch a solid state ac relay such as a crydom D1210 (for 120vac
> @ 10 amps)
> or crydom d2410 (for 240vac @ 10 amps). The crydom relays require 3 to 32
> volts dc to switch. I recommend using a transistor switch
> between the stamp
> and the crydom relays.
>
> For control configurations using a stamp and transistor
> switching, check my
> web site.
>
> Jim
>
> http://www.geocities.com/jimforkin2003
>
>
Original Message
> From: James R. Parish [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=rSquM15PiQPtQ-lPhGmwsl43VegEUqZnT2pQ8GzMNCu_K37G69zBG6HG7STteOCpoliMcb4-crZsrXwQog]JamesParish@J...[/url
> Sent: Friday, April 04, 2003 7:20 AM
> To: basicstamps@yahoogroups.com
> Subject: RE: [noparse][[/noparse]basicstamps] a/c coil transient suppression
>
>
> I would use a CRYDOM solid state relay with ZERO CROSS switching
> instead of
> a relay.
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2519525232&cate
> gory=4660
>
>
>
>
Original Message
> From: Dave [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=ZwR8hbq_xICkM79yvSVGF3HJopmNzPq5x8cGdm9_iXNRujFYXf9uUvkL5dSI4UuliNyfmqKf_Wnk_tgUYyyn]dokagaki@w...[/url
> Sent: Friday, April 04, 2003 12:53 AM
> To: basicstamps@yahoogroups.com
> Subject: [noparse][[/noparse]basicstamps] a/c coil transient suppression
>
> Hi folks,
>
> I'm new to the group and to stamps, so thanks in advance.
>
> Here's the situation: I've got a bs2 controlling a 5vdc relay
> which switches
> a 24vac sprinkler valve controller. The power supply for the
> whole setup is
> a 24vac transformer; I'm using a bridge and regulator to cut it
> down to 5vdc
> for the electronics (with lots of filter caps) and it also powers
> the valve
> selenoid directly via the relay. I've got a rectifier across the
> relay coil
> to clamp spikes, but I have a feeling I need something across the selenoid
> (something called a snubber, perhaps?) to block spikes generated by it
> during switching. The system behaves somewhat irratically when
> the selenoid
> is switched on and off (scope -- set for a/c, 2v/div -- seems to show
> occasional spikes during the switching), it behaves fine without the
> selenoid, and also with the selenoid if I put a cap across it
> (probably not
> a great idea since it's driven by a/c).
>
> I'm not that familiar with a/c circuit transient suppression, and would
> appreciate any insights.
>
> thanks,
>
>
> d...
>
> **************************************************************************
> * David Okagaki dokagaki@w...
> *
> * "The light at the end of the tunnel is that of the on coming train!"
> *
> **************************************************************************
>
>
> 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/
>
>
>
> 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/
>
>
working you don't know it until something else fails.
A better solution is to put a snubber in parallel with the coil. A snubber s
just a cap and resistor in series. Put this in parallel with the coil.
Typical values are .22uf cap and 100 to 1k ohms for the resistor. Use 1/2 to
1 watt resistors. The values will vary depending on the voltage and current
draw of the coil.
If the resistor you are using gets warm try a larger value.
Check out Allied Electronics for pre built Snubbers.
<A
HREF="http://www.alliedelec.com/catalog/pf.asp?FN=159.pdf">http://www.alliedelec\
.com/catalog/pf.asp?FN=159.pdf</A>
They are pricey, but are a single unit.
Good Luck,
Alan Bradford
Plasma Technologies
[noparse][[/noparse]Non-text portions of this message have been removed]
be a problem if the fuse isn't in the right place<G>. I have used back
to back zener diodes, and/or transorbs (zener diodes made specifically
for surge protection. But a snubber is excellent, and likely you have
one in your box. Try one, put an oscilloscope across the line and see
how it does<G>.
Original Message
From: plasmastamp@a... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=OUlq1qdlHqohzjqaInVuE7Mapy5gtlT_4OwjedgIPPkLJyHDD_4T-IPqZQeaD4KOolrf8bXlGtILKw]plasmastamp@a...[/url
Sent: Saturday, April 05, 2003 6:59 PM
To: basicstamps@yahoogroups.com
Subject: Re: [noparse][[/noparse]basicstamps] a/c coil transient suppression
You have to watch out for MOV's. They have a lifetime issue. When they
stop
working you don't know it until something else fails.
A better solution is to put a snubber in parallel with the coil. A
snubber s
just a cap and resistor in series. Put this in parallel with the coil.
Typical values are .22uf cap and 100 to 1k ohms for the resistor. Use
1/2 to
1 watt resistors. The values will vary depending on the voltage and
current
draw of the coil.
If the resistor you are using gets warm try a larger value. Check out
Allied Electronics for pre built Snubbers.
<A
HREF="http://www.alliedelec.com/catalog/pf.asp?FN=159.pdf">http://www.al
liedelec.com/catalog/pf.asp?FN=159.pdf</A>
They are pricey, but are a single unit.
Good Luck,
Alan Bradford
Plasma Technologies
[noparse][[/noparse]Non-text portions of this message have been removed]
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/