transistor switch
Archiver
Posts: 46,084
I need to actuate a 12v solenoid and control it with the 5v output of
the Stamp.
I have a TIP31c npn transistor and the resistance of the solenoid is
90 ohms.
How do I bias this transistor to act like a switch, switching 12volts
to actuate the solenoid?
Thanks
Ed Lentz
Elentz@e...
the Stamp.
I have a TIP31c npn transistor and the resistance of the solenoid is
90 ohms.
How do I bias this transistor to act like a switch, switching 12volts
to actuate the solenoid?
Thanks
Ed Lentz
Elentz@e...
Comments
Your 12V solenoid will draw~ 12V/90 ohms, or 133 ma. The TIP31C data sheet
indicates that this transistor will saturate nicely at this collector
current with ~5 ma. base current. If we allow 0.7V for Vbe, You need a base
resistor of (5-0.7)/.005=860 ohms. The standard value of 820 ohms would do
nicely, 1/8 watt or more.
1) ground the emitter.
2) connect the solenoid from collector to +12V.
3) connect the 820 ohm resistor from the stamp pin to base.
4) connect a diode across the solenoid to protect against the inductive
turn-off spike. The diode should be rated for at least 133 ma and at least
12V. The diode should "point" toward +12V.
Ray McArthur.
Original Message
From: <elentz@e...>
To: <basicstamps@egroups.com>
Sent: Tuesday, April 04, 2000 8:42 PM
Subject: [noparse][[/noparse]basicstamps] transistor switch
> I need to actuate a 12v solenoid and control it with the 5v output of
> the Stamp.
>
> I have a TIP31c npn transistor and the resistance of the solenoid is
> 90 ohms.
>
>
> How do I bias this transistor to act like a switch, switching 12volts
> to actuate the solenoid?
>
> Thanks
>
> Ed Lentz
>
> Elentz@e...
>
>
>
>
http://206.19.206.56/parallel.htm
Look all the way to the bottom and there is a description and picture of
what you want.
Tim
[noparse][[/noparse]Denver, CO]
>
Original Message
> From: elentz@e... [noparse]/noparse]mailto:[url=http://forums.parallaxinc.com/group/basicstamps/post?postID=ARmY9P42YUUZDn2B-0Pya73r4aHVbYLMUO43qI_NSiLv4oTZNN-e-U7Gum_4VZWfoPR9HrSyOa7MD5b2EuM8zw]elentz@e...[/url
> Sent: Tuesday, April 04, 2000 6:43 PM
> To: basicstamps@egroups.com
> Subject: [noparse][[/noparse]basicstamps] transistor switch
>
>
> I need to actuate a 12v solenoid and control it with the 5v output of
> the Stamp.
>
> I have a TIP31c npn transistor and the resistance of the solenoid is
> 90 ohms.
>
>
> How do I bias this transistor to act like a switch, switching 12volts
> to actuate the solenoid?
>
> Thanks
>
> Ed Lentz
>
> Elentz@e...
>
>
>
>
>
another is to use a power mosfet
if all else fails get a $2- $3 radio shack relay that has a coil than
directly runs off low power logic signals
richard
Original Message
From: <elentz@e...>
To: <basicstamps@egroups.com>
Sent: Tuesday, April 04, 2000 7:42 PM
Subject: [noparse][[/noparse]basicstamps] transistor switch
> I need to actuate a 12v solenoid and control it with the 5v output of
> the Stamp.
>
> I have a TIP31c npn transistor and the resistance of the solenoid is
> 90 ohms.
>
>
> How do I bias this transistor to act like a switch, switching 12volts
> to actuate the solenoid?
>
> Thanks
>
> Ed Lentz
>
> Elentz@e...
>
>
>
>
I drew out the circuit because I can remember circuits a whole lot longer
than I can words
even though I didn't ask the question - thanks for taking the time to answer
it
richard
Original Message
From: rjmca <rjmca@w...>
To: <basicstamps@egroups.com>
Sent: Tuesday, April 04, 2000 8:40 PM
Subject: Re: [noparse][[/noparse]basicstamps] transistor switch
> Ed:
> Your 12V solenoid will draw~ 12V/90 ohms, or 133 ma. The TIP31C data
sheet
> indicates that this transistor will saturate nicely at this collector
> current with ~5 ma. base current. If we allow 0.7V for Vbe, You need a
base
> resistor of (5-0.7)/.005=860 ohms. The standard value of 820 ohms would
do
> nicely, 1/8 watt or more.
>
> 1) ground the emitter.
> 2) connect the solenoid from collector to +12V.
> 3) connect the 820 ohm resistor from the stamp pin to base.
> 4) connect a diode across the solenoid to protect against the inductive
> turn-off spike. The diode should be rated for at least 133 ma and at
least
> 12V. The diode should "point" toward +12V.
>
> Ray McArthur.
>
>
Original Message
> From: <elentz@e...>
> To: <basicstamps@egroups.com>
> Sent: Tuesday, April 04, 2000 8:42 PM
> Subject: [noparse][[/noparse]basicstamps] transistor switch
>
>
> > I need to actuate a 12v solenoid and control it with the 5v output of
> > the Stamp.
> >
> > I have a TIP31c npn transistor and the resistance of the solenoid is
> > 90 ohms.
> >
> >
> > How do I bias this transistor to act like a switch, switching 12volts
> > to actuate the solenoid?
> >
> > Thanks
> >
> > Ed Lentz
> >
> > Elentz@e...
> >
> >
> >
> >
>
>
>
>
> At 10:51 AM -0400 4/5/00, Bruce Bates wrote:
> >
> >At 07:54 AM 4/5/00 -0500, dakota promulgated:
> > >One way is to just saturate the transistor like a switch
> > >
> > >another is to use a power mosfet
> > >
> > >if all else fails get a $2- $3 radio shack relay that has a coil than
> > >directly runs off low power logic signals
> >
> >Just to add another option -
> >
> >a solid state relay
>
> gotta be careful here.
>
> MOST solid state relays are designed for AC and NEED AC in order to 'turn
off'.
>
> Most of them will turn ON a DC current but will LATCH in the on state
> regardless of your input signal. (IIRC)
>
> -. .-. .-. .-. .-. .-. .-. .-. .-. .-
> \ / \ / \ N / \ C / \ S / \ S / \ M / \ / \ /
> `-' `-' `-' `-' `-' `-' `-' `-' `-'
> Chuck Britton Education is what is left when
> britton@a... you have forgotten everything
> North Carolina School of Science & Math you learned in school.
> (919) 286-3366 x224 Albert Einstein, 1936
Just my .02 here.
I had a similar question a while back. Someone on the list recommended solid
state relays. I purchased four (AQZ102) These are dc relays. They have been
cycled repeatedly for hours without any failure (I've been doing some long term
usability testing to see if they would hold up).
I'll have to look up where I got them and who made them..But would gladly do so
if
you want the information.
Rus
--
Rus Hardy
"Lucky Devil"
Keeper of the Bucky-n-Thrifty Flame
http://www.bluedestiny.com/Anatomical/Index.shtml
"my mind wanders....I'm just along for the ride"
>One way is to just saturate the transistor like a switch
>
>another is to use a power mosfet
>
>if all else fails get a $2- $3 radio shack relay that has a coil than
>directly runs off low power logic signals
Just to add another option -
a solid state relay
>
>
>
>richard
>
>
>
>
Original Message
>From: <elentz@e...>
>To: <basicstamps@egroups.com>
>Sent: Tuesday, April 04, 2000 7:42 PM
>Subject: [noparse][[/noparse]basicstamps] transistor switch
>
>
>> I need to actuate a 12v solenoid and control it with the 5v output of
>> the Stamp.
>>
>> I have a TIP31c npn transistor and the resistance of the solenoid is
>> 90 ohms.
>>
>>
>> How do I bias this transistor to act like a switch, switching 12volts
>> to actuate the solenoid?
>>
>> Thanks
>>
>> Ed Lentz
>>
>> Elentz@e...
>>
>>
>>
>>
>
>
>
>
>
>
>At 07:54 AM 4/5/00 -0500, dakota promulgated:
> >One way is to just saturate the transistor like a switch
> >
> >another is to use a power mosfet
> >
> >if all else fails get a $2- $3 radio shack relay that has a coil than
> >directly runs off low power logic signals
>
>Just to add another option -
>
>a solid state relay
gotta be careful here.
MOST solid state relays are designed for AC and NEED AC in order to 'turn off'.
Most of them will turn ON a DC current but will LATCH in the on state
regardless of your input signal. (IIRC)
-. .-. .-. .-. .-. .-. .-. .-. .-. .-
\ / \ / \ N / \ C / \ S / \ S / \ M / \ / \ /
`-' `-' `-' `-' `-' `-' `-' `-' `-'
Chuck Britton Education is what is left when
britton@a... you have forgotten everything
North Carolina School of Science & Math you learned in school.
(919) 286-3366 x224 Albert Einstein, 1936
>At 10:51 AM -0400 4/5/00, Bruce Bates wrote:
>>
>>At 07:54 AM 4/5/00 -0500, dakota promulgated:
>> >One way is to just saturate the transistor like a switch
>> >
>> >another is to use a power mosfet
>> >
>> >if all else fails get a $2- $3 radio shack relay that has a coil than
>> >directly runs off low power logic signals
>>
>>Just to add another option -
>>
>>a solid state relay
>
>gotta be careful here.
>
>MOST solid state relays are designed for AC and NEED AC in order to 'turn
off'.
Depends upon the unit you purchase.
>
>Most of them will turn ON a DC current but will LATCH in the on state
>regardless of your input signal. (IIRC)
See above
>
> -. .-. .-. .-. .-. .-. .-. .-. .-. .-
> \ / \ / \ N / \ C / \ S / \ S / \ M / \ / \ /
> `-' `-' `-' `-' `-' `-' `-' `-' `-'
>Chuck Britton Education is what is left when
>britton@a... you have forgotten everything
>North Carolina School of Science & Math you learned in school.
>(919) 286-3366 x224 Albert Einstein, 1936
>
>
>
>
>Chuck Britton wrote:
>
>> At 10:51 AM -0400 4/5/00, Bruce Bates wrote:
>> >
>> >At 07:54 AM 4/5/00 -0500, dakota promulgated:
>> > >One way is to just saturate the transistor like a switch
>> > >
>> > >another is to use a power mosfet
>> > >
>> > >if all else fails get a $2- $3 radio shack relay that has a coil than
>> > >directly runs off low power logic signals
>> >
>> >Just to add another option -
>> >
>> >a solid state relay
>>
>> gotta be careful here.
>>
>> MOST solid state relays are designed for AC and NEED AC in order to
'turn off'.
>>
>> Most of them will turn ON a DC current but will LATCH in the on state
>> regardless of your input signal. (IIRC)
>>
>> -. .-. .-. .-. .-. .-. .-. .-. .-.
.-
>> \ / \ / \ N / \ C / \ S / \ S / \ M / \ / \ /
>> `-' `-' `-' `-' `-' `-' `-' `-' `-'
>> Chuck Britton Education is what is
left when
>> britton@a... you have forgotten
everything
>> North Carolina School of Science & Math you learned in school.
>> (919) 286-3366 x224 Albert Einstein,
1936
>
>Just my .02 here.
>
>I had a similar question a while back. Someone on the list recommended
solid
>state relays. I purchased four (AQZ102) These are dc relays. They have
been
>cycled repeatedly for hours without any failure (I've been doing some long
term
>usability testing to see if they would hold up).
>
>I'll have to look up where I got them and who made them..But would gladly
do so if
>you want the information.
Thanks for the confirmation Rus - I would had to dig my dox out.
Bruce
>
>Rus
>
>--
>Rus Hardy
>"Lucky Devil"
>Keeper of the Bucky-n-Thrifty Flame
>http://www.bluedestiny.com/Anatomical/Index.shtml
>"my mind wanders....I'm just along for the ride"
>
>
>
>
>
>
about 5 large output mosfets with ttl level gates? (IRL3102 by IRF)How do
you protect the micro? Considering a gate "on" voltage of 2.7vdc and a max
gate voltage of 10vdc, a source voltage of 12vdc, 20 amps and more at
startup, the motor is brushless dc and I'm told there will be a voltage
spike when it shuts down. What if I wanted to pulse the gate current to
achieve speed control. How would I build the h-bridge to change motor
direction and do braking? Is there a way to make it rs-232 controlled?
Bill
dakota wrote:
> One way is to just saturate the transistor like a switch
>
> another is to use a power mosfet
>
> if all else fails get a $2- $3 radio shack relay that has a coil than
> directly runs off low power logic signals
>
> richard
>
>
Original Message
> From: <elentz@e...>
> To: <basicstamps@egroups.com>
> Sent: Tuesday, April 04, 2000 7:42 PM
> Subject: [noparse][[/noparse]basicstamps] transistor switch
>
> > I need to actuate a 12v solenoid and control it with the 5v output of
> > the Stamp.
> >
> > I have a TIP31c npn transistor and the resistance of the solenoid is
> > 90 ohms.
> >
> >
> > How do I bias this transistor to act like a switch, switching 12volts
> > to actuate the solenoid?
> >
> > Thanks
> >
> > Ed Lentz
> >
> > Elentz@e...
> >
> >
> >
> >
the internet?
Bill Katakis wrote:
> How would you drive the mosfet? What kind of driver if you wanted to run
> about 5 large output mosfets with ttl level gates? (IRL3102 by IRF)How do
> you protect the micro? Considering a gate "on" voltage of 2.7vdc and a max
> gate voltage of 10vdc, a source voltage of 12vdc, 20 amps and more at
> startup, the motor is brushless dc and I'm told there will be a voltage
> spike when it shuts down. What if I wanted to pulse the gate current to
> achieve speed control. How would I build the h-bridge to change motor
> direction and do braking? Is there a way to make it rs-232 controlled?
>
> Bill
>
> dakota wrote:
>
> > One way is to just saturate the transistor like a switch
> >
> > another is to use a power mosfet
> >
> > if all else fails get a $2- $3 radio shack relay that has a coil than
> > directly runs off low power logic signals
> >
> > richard
> >
> >
Original Message
> > From: <elentz@e...>
> > To: <basicstamps@egroups.com>
> > Sent: Tuesday, April 04, 2000 7:42 PM
> > Subject: [noparse][[/noparse]basicstamps] transistor switch
> >
> > > I need to actuate a 12v solenoid and control it with the 5v output of
> > > the Stamp.
> > >
> > > I have a TIP31c npn transistor and the resistance of the solenoid is
> > > 90 ohms.
> > >
> > >
> > > How do I bias this transistor to act like a switch, switching 12volts
> > > to actuate the solenoid?
> > >
> > > Thanks
> > >
> > > Ed Lentz
> > >
> > > Elentz@e...
> > >
> > >
> > >
> > >