IR Opto-Interupt Circuit Trouble
Archiver
Posts: 46,084
Hello,
I'm trying to set up an infared opto-interrupt circuit and am having
troubles. I'm using the the Fairchild Opto-Logic sensors (QSE159
available from digikey and mouser) and some IR Leds.
http://www.fairchildsemi.com/pf/QS/QSE159.html
These sensors are an "all in one" package that from the schematic
seems easy to hook up. They have three pins, VCC, GND, and VOUT.
But not matter what I try, I can't get a signal out of the VOUT. The
stamp doesn't respond to it, and I can see that there is nothing
happening with my volt meter.
Here are some assumptions that I've made based on limited electronics
knowledge so please correct me if I'm wrong...
1. The sensor's output is "open collector" instead of "totem pole",
I've assumed that this means it gives a full 5 volts from the VOUT
pin, similar to a switch that would be connected to VCC. I have
thought that the "totem pole" version would output current from it's
own internal voltage regulator, but I'm not sure.
2. The sensor is inverted, so when not receiving an IR beam the VOUT
pin should be high. When IR is detected, VOUT should go low.
One of the major annoyances about IR LEDs is you can't see them! But
I've got a regular LED running in parallel with IR LED so I can see
that it is on. Maybe I should use a different sensor all together.
Any suggestions will be appreciated.
Thanks,
Stewart
--
Stewart Mayer, stewlist@k... on 11/15/2001
I'm trying to set up an infared opto-interrupt circuit and am having
troubles. I'm using the the Fairchild Opto-Logic sensors (QSE159
available from digikey and mouser) and some IR Leds.
http://www.fairchildsemi.com/pf/QS/QSE159.html
These sensors are an "all in one" package that from the schematic
seems easy to hook up. They have three pins, VCC, GND, and VOUT.
But not matter what I try, I can't get a signal out of the VOUT. The
stamp doesn't respond to it, and I can see that there is nothing
happening with my volt meter.
Here are some assumptions that I've made based on limited electronics
knowledge so please correct me if I'm wrong...
1. The sensor's output is "open collector" instead of "totem pole",
I've assumed that this means it gives a full 5 volts from the VOUT
pin, similar to a switch that would be connected to VCC. I have
thought that the "totem pole" version would output current from it's
own internal voltage regulator, but I'm not sure.
2. The sensor is inverted, so when not receiving an IR beam the VOUT
pin should be high. When IR is detected, VOUT should go low.
One of the major annoyances about IR LEDs is you can't see them! But
I've got a regular LED running in parallel with IR LED so I can see
that it is on. Maybe I should use a different sensor all together.
Any suggestions will be appreciated.
Thanks,
Stewart
--
Stewart Mayer, stewlist@k... on 11/15/2001
Comments
1) An open collector output can be described as a single pole single throw
switch.
2) The transistor is photo sensitive, hence it only operates when
light is falling on it.
Light falls on the transistor, the transistor switches on (or analogously
the SPST switch turns on).
The open collector output can only connect two things together. In this
case (I'm guessing) ground and VOUT. With full bridge outputs, there are
(at least) two transistors, one connects VOUT to ground, the other to VCC.
You'll need to use a pullup resistor between VCC and VOUT. 10kohms should
work. When the transistor is turned off, the pullup resistor pulls the
voltage on VOUT up to VCC. When the transistor is turned on, it pulls the
voltage on VOUT close to GND.
You can put an LED on the output of the device, in parallel with the pullup
resistor. That way you'll know what the open collector output is doing.
Luke.
On Thu, 15 Nov 2001, Stewart Mayer wrote:
M> Hello,
M>
M> I'm trying to set up an infared opto-interrupt circuit and am having
M> troubles. I'm using the the Fairchild Opto-Logic sensors (QSE159
M> available from digikey and mouser) and some IR Leds.
M>
M> http://www.fairchildsemi.com/pf/QS/QSE159.html
M>
M> These sensors are an "all in one" package that from the schematic
M> seems easy to hook up. They have three pins, VCC, GND, and VOUT.
M> But not matter what I try, I can't get a signal out of the VOUT. The
M> stamp doesn't respond to it, and I can see that there is nothing
M> happening with my volt meter.
M>
M> Here are some assumptions that I've made based on limited electronics
M> knowledge so please correct me if I'm wrong...
M>
M> 1. The sensor's output is "open collector" instead of "totem pole",
M> I've assumed that this means it gives a full 5 volts from the VOUT
M> pin, similar to a switch that would be connected to VCC. I have
M> thought that the "totem pole" version would output current from it's
M> own internal voltage regulator, but I'm not sure.
M>
M> 2. The sensor is inverted, so when not receiving an IR beam the VOUT
M> pin should be high. When IR is detected, VOUT should go low.
M>
M> One of the major annoyances about IR LEDs is you can't see them! But
M> I've got a regular LED running in parallel with IR LED so I can see
M> that it is on. Maybe I should use a different sensor all together.
M> Any suggestions will be appreciated.
M>
M> Thanks,
M> Stewart
M>
M> --
M> Stewart Mayer, stewlist@k... on 11/15/2001
M>
M>
M>
M> To UNSUBSCRIBE, just send mail to:
M> basicstamps-unsubscribe@yahoogroups.com
M> from the same email address that you subscribed. Text in the Subject and
Body of the message will be ignored.
M>
M>
M> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
M>
M>
--
'80 (ex)KE38 '86 ST141 '84 AE86 '90 ST185
buying one of those test cards from Radio Shack or using a camcorder to
verify its working.
Secondly, you need to be sure the only thing you are trying to drive with
the output of the module is a stamp pin or a meter.
In glancing at the diagram, it looks like you should see an output from the
module when its not detecting I/R, and the output should drop to 0 volts
when I/R is detected. In any case, try shielding the module and see what
happens -- some of these things pick up I/R from other sources and trigger
when they should not.
Original Message
> I'm trying to set up an infared opto-interrupt circuit and am having
> troubles. I'm using the the Fairchild Opto-Logic sensors (QSE159
> available from digikey and mouser) and some IR Leds.
>
> http://www.fairchildsemi.com/pf/QS/QSE159.html
>
> These sensors are an "all in one" package that from the schematic
> seems easy to hook up. They have three pins, VCC, GND, and VOUT.
> But not matter what I try, I can't get a signal out of the VOUT. The
> stamp doesn't respond to it, and I can see that there is nothing
> happening with my volt meter.
>
> Here are some assumptions that I've made based on limited electronics
> knowledge so please correct me if I'm wrong...
>
> 1. The sensor's output is "open collector" instead of "totem pole",
> I've assumed that this means it gives a full 5 volts from the VOUT
> pin, similar to a switch that would be connected to VCC. I have
> thought that the "totem pole" version would output current from it's
> own internal voltage regulator, but I'm not sure.
>
> 2. The sensor is inverted, so when not receiving an IR beam the VOUT
> pin should be high. When IR is detected, VOUT should go low.
>
> One of the major annoyances about IR LEDs is you can't see them! But
> I've got a regular LED running in parallel with IR LED so I can see
> that it is on. Maybe I should use a different sensor all together.
> Any suggestions will be appreciated.
tomorrow and let you know what the problem was.
Stew
On Fri, 16 Nov 2001 13:16:15 +1100 (EST), Luke Szymanski wrote:
>Hi,
>
>1) An open collector output can be described as a single pole single
>throw
>switch.
>
>2) The transistor is photo sensitive, hence it only operates when
>light is falling on it.
>
>Light falls on the transistor, the transistor switches on (or
>analogously
>the SPST switch turns on).
>
>The open collector output can only connect two things together. In
>this
>case (I'm guessing) ground and VOUT. With full bridge outputs, there
>are
>(at least) two transistors, one connects VOUT to ground, the other
>to VCC.
>
>You'll need to use a pullup resistor between VCC and VOUT. 10kohms
>should
>work. When the transistor is turned off, the pullup resistor pulls
>the
>voltage on VOUT up to VCC. When the transistor is turned on, it
>pulls the
>voltage on VOUT close to GND.
>
>You can put an LED on the output of the device, in parallel with the
>pullup
>resistor. That way you'll know what the open collector output is
>doing.
>
>Luke.
>
>On Thu, 15 Nov 2001, Stewart Mayer wrote:
>
>M> Hello,
>M>
>M> I'm trying to set up an infared opto-interrupt circuit and am
>having
>M> troubles. I'm using the the Fairchild Opto-Logic sensors (QSE159
>M> available from digikey and mouser) and some IR Leds.
>M>
>M> http://www.fairchildsemi.com/pf/QS/QSE159.html
>M>
>M> These sensors are an "all in one" package that from the schematic
>M> seems easy to hook up. They have three pins, VCC, GND, and VOUT.
>
>M> But not matter what I try, I can't get a signal out of the VOUT.
>The
>M> stamp doesn't respond to it, and I can see that there is nothing
>M> happening with my volt meter.
>M>
>M> Here are some assumptions that I've made based on limited
>electronics
>M> knowledge so please correct me if I'm wrong...
>M>
>M> 1. The sensor's output is "open collector" instead of "totem
>pole",
>M> I've assumed that this means it gives a full 5 volts from the
>VOUT
>M> pin, similar to a switch that would be connected to VCC. I have
>M> thought that the "totem pole" version would output current from
>it's
>M> own internal voltage regulator, but I'm not sure.
>M>
>M> 2. The sensor is inverted, so when not receiving an IR beam the
>VOUT
>M> pin should be high. When IR is detected, VOUT should go low.
>M>
>M> One of the major annoyances about IR LEDs is you can't see them!
>But
>M> I've got a regular LED running in parallel with IR LED so I can
>see
>M> that it is on. Maybe I should use a different sensor all
>together.
>M> Any suggestions will be appreciated.
>M>
>M> Thanks,
>M> Stewart
>M>
>M> --
>M> Stewart Mayer, stewlist@k... on 11/15/2001
>M>
>M>
>M>
>M> To UNSUBSCRIBE, just send mail to:
>M> basicstamps-unsubscribe@yahoogroups.com
>M> from the same email address that you subscribed. Text in the
>Subject and Body of the message will be ignored.
>M>
>M>
>M> Your use of Yahoo! Groups is subject to
>http://docs.yahoo.com/info/terms/
>M>
>M>
>
--
Stewart Mayer, stewlist@k... on 11/15/2001
get nothing. Since the sensor has inverted output I should be
getting a signal from VOUT. I may have fried it by trying to drive a
LED, I see now that the output current is only 100ua.
I'll order some more $.30 parts and experiment some more.
Thanks,
Stewart
On Thu, 15 Nov 2001 21:14:00 -0600, Rodent wrote:
>First you need to figure out if your I/R LED is really working. I
>suggest
>buying one of those test cards from Radio Shack or using a camcorder
>to
>verify its working.
>
>Secondly, you need to be sure the only thing you are trying to drive
>with
>the output of the module is a stamp pin or a meter.
>
>In glancing at the diagram, it looks like you should see an output
>from the
>module when its not detecting I/R, and the output should drop to 0
>volts
>when I/R is detected. In any case, try shielding the module and see
>what
>happens -- some of these things pick up I/R from other sources and
>trigger
>when they should not.
>
>
Original Message
>
>>I'm trying to set up an infared opto-interrupt circuit and am
>>having
>>troubles. I'm using the the Fairchild Opto-Logic sensors (QSE159
>>available from digikey and mouser) and some IR Leds.
>>
>>http://www.fairchildsemi.com/pf/QS/QSE159.html
>>
>>These sensors are an "all in one" package that from the schematic
>>seems easy to hook up. They have three pins, VCC, GND, and VOUT.
>>But not matter what I try, I can't get a signal out of the VOUT.
>>The
>>stamp doesn't respond to it, and I can see that there is nothing
>>happening with my volt meter.
>>
>>Here are some assumptions that I've made based on limited
>>electronics
>>knowledge so please correct me if I'm wrong...
>>
>>1. The sensor's output is "open collector" instead of "totem
>>pole",
>>I've assumed that this means it gives a full 5 volts from the VOUT
>>pin, similar to a switch that would be connected to VCC. I have
>>thought that the "totem pole" version would output current from
>>it's
>>own internal voltage regulator, but I'm not sure.
>>
>>2. The sensor is inverted, so when not receiving an IR beam the
>>VOUT
>>pin should be high. When IR is detected, VOUT should go low.
>>
>>One of the major annoyances about IR LEDs is you can't see them!
>>But
>>I've got a regular LED running in parallel with IR LED so I can see
>>that it is on. Maybe I should use a different sensor all together.
>>Any suggestions will 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/
>
>
--
Stewart Mayer, stewlist@k... on 11/16/2001