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Hello,

I would like to know what would be the best approach to switch a 2 to
3A, 24Vdc load on and off using the basicx 24. I have looked at a
transistor but I can't find one that has a low enough base current for
the basicx. I am starting to think that a relay may be more
appropriate here.

thanks for any input,

FlyerX
------------------------------------



(You need to be a member of basicx -- send a blank email to basicx-subscribe@yahoogroups.com )

Hi,

You can use a mosfet transistor with a transistor between the BX 24 and the mosfet as isolation or like you said a relay but a solid state relay. You can connect the output directly to the solid state? with no problem. There are relays AC/DC relay from 1 amp to 100 amps and? 5 volts AC/DC / 280 volts AC/DC.

rosarite

-----Original Message-----
From: flyerx_2000
To: b...@yahoogroups.com
Sent: Wed, 23 Jul 2008 2:58 am
Subject: [BasicX] Switching a large DC load

Hello,

I would like to know what would be the best approach to switch a 2 to

3A, 24Vdc load on and off using the basicx 24. I have looked at a

transistor but I can't find one that has a low enough base current for

the basicx. I am starting to think that a relay may be more

appropriate here.

thanks for any input,

FlyerX

[Non-text portions of this message have been removed]
------------------------------------



(You need to be a member of basicx -- send a blank email to basicx-subscribe@yahoogroups.com )

Switch a relay coil using a transistor.

Like here:

http://www.wam.umd.edu/~toh/ElectroSim/relay.html

On Wed, Jul 23, 2008 at 3:58 AM, flyerx_2000 wrote:

> Hello,
>
> I would like to know what would be the best approach to switch a 2 to
> 3A, 24Vdc load on and off using the basicx 24. I have looked at a
> transistor but I can't find one that has a low enough base current for
> the basicx. I am starting to think that a relay may be more
> appropriate here.
>
> thanks for any input,
>
> FlyerX
>
[Non-text portions of this message have been removed]
------------------------------------



(You need to be a member of basicx -- send a blank email to basicx-subscribe@yahoogroups.com )

You may be right about using a relay. Short of using an amp to drive the correct transistor I was wondering if you could do the switching
in the AC mode. I don't know if you can. By say that you are going thru a step down transformer, you could switch the load using a triac at
an even lower current level. The only reason I sugjest this posibility is because I did this my self once and it worked out well.
Good luck

----- Original Message ----
From: flyerx_2000
To: b...@yahoogroups.com
Sent: Wednesday, July 23, 2008 12:58:08 AM
Subject: [BasicX] Switching a large DC load
Hello,

I would like to know what would be the best approach to switch a 2 to
3A, 24Vdc load on and off using the basicx 24. I have looked at a
transistor but I can't find one that has a low enough base current for
the basicx. I am starting to think that a relay may be more
appropriate here.

thanks for any input,

FlyerX

[Non-text portions of this message have been removed]
------------------------------------



(You need to be a member of basicx -- send a blank email to basicx-subscribe@yahoogroups.com )

What is the load? Two or three Amps isn't difficult at all if it is a
resistive load, a little more difficult if it is an inductive load. I
PWM an 8-Amp 12v lamp (that's warm; it spikes at cold startup to about
40 Amps), easily with a pair of FETs through an optoisolator (so the FET
gate drive is at supply level). Similar to this extinct product:
http://web.archive.org/web/20050830123718/www.picobotics.com/PortBooster.html

Tom

------------------------------------



(You need to be a member of basicx -- send a blank email to basicx-subscribe@yahoogroups.com )

Thanks everyone for the input. I decided to go with a solid-state
relay similar to the omron g3tc series. It is designed for
microcontrollers.

FlyerX

--- In b...@yahoogroups.com, "flyerx_2000" wrote:
>
> Hello,
>
> I would like to know what would be the best approach to switch a 2 to
> 3A, 24Vdc load on and off using the basicx 24. I have looked at a
> transistor but I can't find one that has a low enough base current for
> the basicx. I am starting to think that a relay may be more
> appropriate here.
>
> thanks for any input,
>
> FlyerX
>

------------------------------------



(You need to be a member of basicx -- send a blank email to basicx-subscribe@yahoogroups.com )

Tom,

It could be resistive or inductive: a lamp, horn or any other type of
alarm-type device.

FlyerX
--- In b...@yahoogroups.com, Tom Becker wrote:
>
> What is the load? Two or three Amps isn't difficult at all if it is a
> resistive load, a little more difficult if it is an inductive load. I
> PWM an 8-Amp 12v lamp (that's warm; it spikes at cold startup to about
> 40 Amps), easily with a pair of FETs through an optoisolator (so the
FET
> gate drive is at supply level). Similar to this extinct product:
>
http://web.archive.org/web/20050830123718/www.picobotics.com/PortBooster.html
>
> Tom
>

------------------------------------



(You need to be a member of basicx -- send a blank email to basicx-subscribe@yahoogroups.com )

Is there any advantage to swinging the gate with full supply voltage? I
have a 600 volt 12 amp MOSFET that I'm driving with a 10V supply feeding
a two transistor rig on the gate using PWM with a 320V supply. I'm
using 2N3904 & 2N3906 on the gate and I do know they are not rated for
that high a voltage so I would have to find a pair of transistors with a
bit higher rating.

From: b...@yahoogroups.com [mailto:b...@yahoogroups.com] On Behalf
Of Tom Becker
Sent: Wednesday, July 23, 2008 4:18 PM
To: b...@yahoogroups.com
Subject: Re: [BasicX] Switching a large DC load

What is the load? Two or three Amps isn't difficult at all if it is a
resistive load, a little more difficult if it is an inductive load. I
PWM an 8-Amp 12v lamp (that's warm; it spikes at cold startup to about
40 Amps), easily with a pair of FETs through an optoisolator (so the FET

gate drive is at supply level). Similar to this extinct product:
http://web.archive.org/web/20050830123718/www.picobotics.com/PortBooster
.html

Tom

[Non-text portions of this message have been removed]
------------------------------------



(You need to be a member of basicx -- send a blank email to basicx-subscribe@yahoogroups.com )