high current solenoid switch with BS2
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Posts: 46,084
I would like to implement a switch capable of operating at 30-40 Amps DC
current only.
I am leaning towards a solenoid design, which would involve only buying a
coupling for my wires that are rated at 30-40 Amps.
The solenoid itself would be powered by my car power supply (12.9 V). I
would like it to be triggered either a basic stamp 2 signal "HIGH" or "LOW."
I know that the BS2 is limited to 20mA source per pin (50mA sync), so I'm
not quite sure how to go about amplifying the 5V signal from the BS2, or
rather amplifying the current from the BS2 (determined by a series
resister). I'm assuming Ill need to use several BJTs to amplify the current
to trigger a 12.9 V automotive solenoid, but I really am not sure. I've
googled a lot....
Is this feasible? Ideally, I would have the coupling between the two dc
wires as an open, and then when the BS2 sends a "HIGH" or "LOW" signal (I
was thinking high....) it would trigger the solenoid to contract and make
contact between the 2 DC wires. Can anyone help me out on this one? Am I
thinking about this the right way? I am open to suggestions that do not
involve solenoid switches, however, my circuit requirements need to be that
it can conduct 30-40Amps ( I haven't found a simple relay to do this much
current). I have found some MOSFETS that operate at high currents, however,
they also require a high VGS (voltage-gate-source) which I am limited by 5V
due to my BS2.
Any suggestions or insights are appreciated!
-- kyle s.
P.S. If ther is any way possible to isolate my BS2 from the the rest of my
circuit I would love to do that to avoid all possible feedback (even though
theoretically IG should be 0 at DC, you never know...)
I'm partial to optical FETS (LEDs which shine "light" on a MOSFET, which
interprets it as a voltage, and thus allows current betwen the source and
drain to flow.
If anyone can think of a different way of coupling then that also would be
appreciated...
current only.
I am leaning towards a solenoid design, which would involve only buying a
coupling for my wires that are rated at 30-40 Amps.
The solenoid itself would be powered by my car power supply (12.9 V). I
would like it to be triggered either a basic stamp 2 signal "HIGH" or "LOW."
I know that the BS2 is limited to 20mA source per pin (50mA sync), so I'm
not quite sure how to go about amplifying the 5V signal from the BS2, or
rather amplifying the current from the BS2 (determined by a series
resister). I'm assuming Ill need to use several BJTs to amplify the current
to trigger a 12.9 V automotive solenoid, but I really am not sure. I've
googled a lot....
Is this feasible? Ideally, I would have the coupling between the two dc
wires as an open, and then when the BS2 sends a "HIGH" or "LOW" signal (I
was thinking high....) it would trigger the solenoid to contract and make
contact between the 2 DC wires. Can anyone help me out on this one? Am I
thinking about this the right way? I am open to suggestions that do not
involve solenoid switches, however, my circuit requirements need to be that
it can conduct 30-40Amps ( I haven't found a simple relay to do this much
current). I have found some MOSFETS that operate at high currents, however,
they also require a high VGS (voltage-gate-source) which I am limited by 5V
due to my BS2.
Any suggestions or insights are appreciated!
-- kyle s.
P.S. If ther is any way possible to isolate my BS2 from the the rest of my
circuit I would love to do that to avoid all possible feedback (even though
theoretically IG should be 0 at DC, you never know...)
I'm partial to optical FETS (LEDs which shine "light" on a MOSFET, which
interprets it as a voltage, and thus allows current betwen the source and
drain to flow.
If anyone can think of a different way of coupling then that also would be
appreciated...
Comments
solenoid and using darlignton power transistor u can do it. But u should
work with two isolated ground. Any spikes will reset your cpu. and u will be
trouble.
Original Message
From: KamaolaKid <KamaolaKid@g...>
To: <basicstamps@yahoogroups.com>
Sent: Saturday, November 16, 2002 4:43 PM
Subject: [noparse][[/noparse]basicstamps] high current solenoid switch with BS2
> I would like to implement a switch capable of operating at 30-40 Amps DC
> current only.
> I am leaning towards a solenoid design, which would involve only buying a
> coupling for my wires that are rated at 30-40 Amps.
> The solenoid itself would be powered by my car power supply (12.9 V). I
> would like it to be triggered either a basic stamp 2 signal "HIGH" or
"LOW."
> I know that the BS2 is limited to 20mA source per pin (50mA sync), so I'm
> not quite sure how to go about amplifying the 5V signal from the BS2, or
> rather amplifying the current from the BS2 (determined by a series
> resister). I'm assuming Ill need to use several BJTs to amplify the
current
> to trigger a 12.9 V automotive solenoid, but I really am not sure. I've
> googled a lot....
> Is this feasible? Ideally, I would have the coupling between the two dc
> wires as an open, and then when the BS2 sends a "HIGH" or "LOW" signal (I
> was thinking high....) it would trigger the solenoid to contract and make
> contact between the 2 DC wires. Can anyone help me out on this one? Am I
> thinking about this the right way? I am open to suggestions that do not
> involve solenoid switches, however, my circuit requirements need to be
that
> it can conduct 30-40Amps ( I haven't found a simple relay to do this much
> current). I have found some MOSFETS that operate at high currents,
however,
> they also require a high VGS (voltage-gate-source) which I am limited by
5V
> due to my BS2.
>
>
> Any suggestions or insights are appreciated!
>
> -- kyle s.
>
> P.S. If ther is any way possible to isolate my BS2 from the the rest of
my
> circuit I would love to do that to avoid all possible feedback (even
though
> theoretically IG should be 0 at DC, you never know...)
> I'm partial to optical FETS (LEDs which shine "light" on a MOSFET, which
> interprets it as a voltage, and thus allows current betwen the source and
> drain to flow.
> If anyone can think of a different way of coupling then that also would be
> appreciated...
>
>
> 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/
>
>
>
my sailboat to parallel the batteries does. It only needs about 1/4 of that
to hold it closed.
You can drive it from the BS2 using a small power transistor - I would use
a Darlington configuration power transistor to reduce the current required
from the BS2. Put a 470 ohm resistor from the BS2 output to the base of the
transistor. The emitter of the transistor goes to ground, and the solenoid
goes from the 12 volt supply to the collector of the transistor.
You need to suppress the large voltage spikes you will get when the current
through the solenoid is cut off. You do this by putting a diode (any old 1
amp diode should do) across the solenoid - the cathode of the diode to the
end connecting to the 12V supply, the anode to the end connected to the
transistor.
Larry
At 06:13 AM 11/16/2002 -0500, you wrote:
>I would like to implement a switch capable of operating at 30-40 Amps DC
>current only.
>I am leaning towards a solenoid design, which would involve only buying a
>coupling for my wires that are rated at 30-40 Amps.
>The solenoid itself would be powered by my car power supply (12.9 V). I
>would like it to be triggered either a basic stamp 2 signal "HIGH" or "LOW."
>I know that the BS2 is limited to 20mA source per pin (50mA sync), so I'm
>not quite sure how to go about amplifying the 5V signal from the BS2, or
>rather amplifying the current from the BS2 (determined by a series
>resister). I'm assuming Ill need to use several BJTs to amplify the current
>to trigger a 12.9 V automotive solenoid, but I really am not sure. I've
>googled a lot....
>Is this feasible? Ideally, I would have the coupling between the two dc
>wires as an open, and then when the BS2 sends a "HIGH" or "LOW" signal (I
>was thinking high....) it would trigger the solenoid to contract and make
>contact between the 2 DC wires. Can anyone help me out on this one? Am I
>thinking about this the right way? I am open to suggestions that do not
>involve solenoid switches, however, my circuit requirements need to be that
>it can conduct 30-40Amps ( I haven't found a simple relay to do this much
>current). I have found some MOSFETS that operate at high currents, however,
>they also require a high VGS (voltage-gate-source) which I am limited by 5V
>due to my BS2.
>
>
>Any suggestions or insights are appreciated!
>
>-- kyle s.
>
>P.S. If ther is any way possible to isolate my BS2 from the the rest of my
>circuit I would love to do that to avoid all possible feedback (even though
>theoretically IG should be 0 at DC, you never know...)
>I'm partial to optical FETS (LEDs which shine "light" on a MOSFET, which
>interprets it as a voltage, and thus allows current betwen the source and
>drain to flow.
>If anyone can think of a different way of coupling then that also would be
>appreciated...
>
>
>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/
Larry Bradley
Orleans (Ottawa), Ontario, CANADA
only need to make one, go to the junk yard and get the relays out of
a newer Dodge Caravan, they're under the hood on the drivers side.
They are 30 amp relays [noparse]:)[/noparse]
Then all you need is solid state relay with isolation to drive the
big relay. One of these should
[url=work...http://dkc3.digikey.com/T023/V5/0804-0807.pdf]work...http://dkc3.digikey.com/T023/V5/0804-0807.pdf[/url]
Either that or a 'normal' optocoupler driving a transistor that
drives the relay ( that sounds messy )
Keith
--- In basicstamps@y..., "KamaolaKid" <KamaolaKid@g...> wrote:
> I would like to implement a switch capable of operating at 30-40
Amps DC
> current only.
> I am leaning towards a solenoid design, which would involve only
buying a
> coupling for my wires that are rated at 30-40 Amps.
> The solenoid itself would be powered by my car power supply (12.9
V). I
> would like it to be triggered either a basic stamp 2 signal "HIGH"
or "LOW."
> I know that the BS2 is limited to 20mA source per pin (50mA sync),
so I'm
> not quite sure how to go about amplifying the 5V signal from the
BS2, or
> rather amplifying the current from the BS2 (determined by a series
> resister). I'm assuming Ill need to use several BJTs to amplify
the current
> to trigger a 12.9 V automotive solenoid, but I really am not sure.
I've
> googled a lot....
> Is this feasible? Ideally, I would have the coupling between the
two dc
> wires as an open, and then when the BS2 sends a "HIGH" or "LOW"
signal (I
> was thinking high....) it would trigger the solenoid to contract
and make
> contact between the 2 DC wires. Can anyone help me out on this
one? Am I
> thinking about this the right way? I am open to suggestions that
do not
> involve solenoid switches, however, my circuit requirements need to
be that
> it can conduct 30-40Amps ( I haven't found a simple relay to do
this much
> current). I have found some MOSFETS that operate at high currents,
however,
> they also require a high VGS (voltage-gate-source) which I am
limited by 5V
> due to my BS2.
>
>
> Any suggestions or insights are appreciated!
>
> -- kyle s.
>
> P.S. If ther is any way possible to isolate my BS2 from the the
rest of my
> circuit I would love to do that to avoid all possible feedback
(even though
> theoretically IG should be 0 at DC, you never know...)
> I'm partial to optical FETS (LEDs which shine "light" on a MOSFET,
which
> interprets it as a voltage, and thus allows current betwen the
source and
> drain to flow.
> If anyone can think of a different way of coupling then that also
would be
> appreciated...
solenoid, go to a camper / RV supply and ask for an auxiliary battery
charging relay. They are similar to a Ford starter solenoid except they are
for continuous duty -- the Ford part will melt in 5-10 minutes. They will
handle mucho current.
> A solenoid might require 1 amp or so to close - at least, the one I use on
> my sailboat to parallel the batteries does. It only needs about 1/4 of
that
> to hold it closed.
>
> You can drive it from the BS2 using a small power transistor - I would use
> a Darlington configuration power transistor to reduce the current required
> from the BS2. Put a 470 ohm resistor from the BS2 output to the base of
the
> transistor. The emitter of the transistor goes to ground, and the solenoid
> goes from the 12 volt supply to the collector of the transistor.
>
> You need to suppress the large voltage spikes you will get when the
current
> through the solenoid is cut off. You do this by putting a diode (any old
1
> amp diode should do) across the solenoid - the cathode of the diode to the
> end connecting to the 12V supply, the anode to the end connected to the
> transistor.
> >I would like to implement a switch capable of operating at 30-40 Amps DC
> >current only.
> >I am leaning towards a solenoid design, which would involve only buying a
> >coupling for my wires that are rated at 30-40 Amps.
> >The solenoid itself would be powered by my car power supply (12.9 V). I
> >would like it to be triggered either a basic stamp 2 signal "HIGH" or
"LOW."
> >I know that the BS2 is limited to 20mA source per pin (50mA sync), so I'm
> >not quite sure how to go about amplifying the 5V signal from the BS2, or
> >rather amplifying the current from the BS2 (determined by a series
> >resister). I'm assuming Ill need to use several BJTs to amplify the
current
> >to trigger a 12.9 V automotive solenoid, but I really am not sure. I've
> >googled a lot....
> >Is this feasible? Ideally, I would have the coupling between the two dc
> >wires as an open, and then when the BS2 sends a "HIGH" or "LOW" signal (I
> >was thinking high....) it would trigger the solenoid to contract and make
> >contact between the 2 DC wires. Can anyone help me out on this one? Am
I
> >thinking about this the right way? I am open to suggestions that do not
> >involve solenoid switches, however, my circuit requirements need to be
that
> >it can conduct 30-40Amps ( I haven't found a simple relay to do this much
> >current). I have found some MOSFETS that operate at high currents,
however,
> >they also require a high VGS (voltage-gate-source) which I am limited by
5V
> >due to my BS2.
I think this is the design I'm going to go with. Although it doesn't
optocouple the solenoid from the bs2, it should do fine if I put a diode in
with the solenoid, like you suggested, so that there will be no feedback
current spikes.
I'll let you know how it works out.
-- Kyle S.
P.S. I have looked at automotive relays, but I haven't found any that are
rated for over 30A. I probably won't hit 30A, but I would like to leave
myself some design room....
Thanks everyone!
Original Message
From: "Larry Bradley" <lhbradley@i...>
To: <basicstamps@yahoogroups.com>
Sent: Saturday, November 16, 2002 11:00 AM
Subject: Re: [noparse][[/noparse]basicstamps] high current solenoid switch with BS2
> A solenoid might require 1 amp or so to close - at least, the one I use on
> my sailboat to parallel the batteries does. It only needs about 1/4 of
that
> to hold it closed.
>
> You can drive it from the BS2 using a small power transistor - I would use
> a Darlington configuration power transistor to reduce the current required
> from the BS2. Put a 470 ohm resistor from the BS2 output to the base of
the
> transistor. The emitter of the transistor goes to ground, and the solenoid
> goes from the 12 volt supply to the collector of the transistor.
>
> You need to suppress the large voltage spikes you will get when the
current
> through the solenoid is cut off. You do this by putting a diode (any old
1
> amp diode should do) across the solenoid - the cathode of the diode to the
> end connecting to the 12V supply, the anode to the end connected to the
> transistor.
>
> Larry
>
> At 06:13 AM 11/16/2002 -0500, you wrote:
> >I would like to implement a switch capable of operating at 30-40 Amps DC
> >current only.
> >I am leaning towards a solenoid design, which would involve only buying a
> >coupling for my wires that are rated at 30-40 Amps.
> >The solenoid itself would be powered by my car power supply (12.9 V). I
> >would like it to be triggered either a basic stamp 2 signal "HIGH" or
"LOW."
> >I know that the BS2 is limited to 20mA source per pin (50mA sync), so I'm
> >not quite sure how to go about amplifying the 5V signal from the BS2, or
> >rather amplifying the current from the BS2 (determined by a series
> >resister). I'm assuming Ill need to use several BJTs to amplify the
current
> >to trigger a 12.9 V automotive solenoid, but I really am not sure. I've
> >googled a lot....
> >Is this feasible? Ideally, I would have the coupling between the two dc
> >wires as an open, and then when the BS2 sends a "HIGH" or "LOW" signal (I
> >was thinking high....) it would trigger the solenoid to contract and make
> >contact between the 2 DC wires. Can anyone help me out on this one? Am
I
> >thinking about this the right way? I am open to suggestions that do not
> >involve solenoid switches, however, my circuit requirements need to be
that
> >it can conduct 30-40Amps ( I haven't found a simple relay to do this much
> >current). I have found some MOSFETS that operate at high currents,
however,
> >they also require a high VGS (voltage-gate-source) which I am limited by
5V
> >due to my BS2.
> >
> >
> >Any suggestions or insights are appreciated!
> >
> >-- kyle s.
> >
> >P.S. If ther is any way possible to isolate my BS2 from the the rest of
my
> >circuit I would love to do that to avoid all possible feedback (even
though
> >theoretically IG should be 0 at DC, you never know...)
> >I'm partial to optical FETS (LEDs which shine "light" on a MOSFET, which
> >interprets it as a voltage, and thus allows current betwen the source and
> >drain to flow.
> >If anyone can think of a different way of coupling then that also would
be
> >appreciated...
> >
> >
> >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/
>
> Larry Bradley
> Orleans (Ottawa), Ontario, CANADA
>
>
> 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/
>
>
them;
http://www.glitchbuster.com
Also they can be easily paralleled for more current handling.
> I haven't found a simple relay to do this much
> current). I have found some MOSFETS that operate at high currents,
> however, they also require a high VGS (voltage-gate-source) which I am
> limited by 5V due to my BS2.
>
>
> Any suggestions or insights are appreciated!
Mike DeMetz N9GEZ
Elkhart, IN
mailto:n9gez@q...
http://www.qsl.net/n9gez