# Help with using a PIR to trigger a NE555

#### AnalogKid

Joined Aug 1, 2013
10,218
You mentioned possibly buying a commercial product to do this. This is not a universe I'm familiar with; can you post a link to something typical? Just curious.

ak

#### AllisonAmg

Joined May 18, 2020
71
You mentioned possibly buying a commercial product to do this. This is not a universe I'm familiar with; can you post a link to something typical? Just curious.

ak
Hi,

To be honest i havent deleved in to the commercial products too much, i have looked at this companies offerings but found them lacking

http://www.blocksignalling.co.uk/index.php/shop/category/view/3

I have ordered the bits needed to make a couple of prototypes, as long as the diagram i sent you is ok i can build it on to bread board

If i was making a simpler but effective version i would have used this as a model http://www.blocksignalling.co.uk/pdfs/99FF6H.pdf

kindest
Allison

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#### AnalogKid

Joined Aug 1, 2013
10,218
Wiring.

Compared to soldering connecting wires directly to the circuit boards, connectors are time-consuming and expensive. But they pay it back very quickly if you have to remove a board from the system for, well, just about anything. I always recommend them, but I recognize that it is a financial decision, sometimes more than technical.

I would use 0.1" pitch headers for all I/O - switches, LEDs, sensors, power - because I have the parts and the crimp tool. The modules you linked to all have field wiring / terminal blocks. If that is what you want, then consider a compromise - terminals blocks that plug onto a pin header. At least for the development / debugging phase, they save tons of time. If you have a favorite connector (or connector style), please post a link or photo.

ak

#### AllisonAmg

Joined May 18, 2020
71
Wiring.

Compared to soldering connecting wires directly to the circuit boards, connectors are time-consuming and expensive. But they pay it back very quickly if you have to remove a board from the system for, well, just about anything. I always recommend them, but I recognize that it is a financial decision, sometimes more than technical.

I would use 0.1" pitch headers for all I/O - switches, LEDs, sensors, power - because I have the parts and the crimp tool. The modules you linked to all have field wiring / terminal blocks. If that is what you want, then consider a compromise - terminals blocks that plug onto a pin header. At least for the development / debugging phase, they save tons of time. If you have a favorite connector (or connector style), please post a link or photo.

ak
Hi,

I am using MB-102 Bread board for prototype and in tend to use D-Sub connectors for connection to the structure & signals.

Allison

#### AllisonAmg

Joined May 18, 2020
71
Hi,

I am using MB-102 Bread board for prototype and in tend to use D-Sub connectors for connection to the structure & signals.

Allison
When you get a moment, i would like to use the circuit you designed for me for a different kind of signal to be used on certain sections of track where it would not be practical to use 2 Sensors. I have enclosed a Flow chart for your information.

Kindest
Allison

#### eetech00

Joined Jun 8, 2013
3,418
I will be building a prototype this weekend (time permitting, hubby is home this weekend !!)... I will then be building the physical signals after i have finished wiring the control panels (1st panel front & wiring pic is enclosed), i am in the midle of wiring the 2nd panel.

I have enclosed a pic of the 2nd Panel and the layout schematic just to give you a flavour of the work i am doing,

Allison

View attachment 208958View attachment 208959
Hi

Nice panel.
I used to design RR traffic control systems for passenger and freight trains (In the US) in my former life.
a few were the largest in the country at the time. Is this a model layout? What gauge? From the discussion, it seems this is similar to the old “line o lite” style traffic control systems. Just curious.,

#### AllisonAmg

Joined May 18, 2020
71
Hi

Nice panel.
I used to design RR traffic control systems for passenger and freight trains (In the US) in my former life.
a few were the largest in the country at the time. Is this a model layout? What gauge? From the discussion, it seems this is similar to the old “line o lite” style traffic control systems. Just curious.,
Hi,

Its a OO gauge (4mm to the Foot) layout.

Allison

#### ericgibbs

Joined Jan 29, 2010
17,150
hi Allison,
Update on the 4093 circuit when using TCRT5000 Sensor modules.
As per your PM test, the TCRT have been disconnected so that you can test the Manual switches, looks OK.

Let me know when the Manual test is working OK, will then try S1 and S2 inputs.

E
Footnote:
The TCRT sensor output is High when activated ie: inverted compared to the original IR sensor, which gave you unusable results.
Cap C2 is used to enable a Latch Reset at Power On
The components inside the boxed dashed line area are the SIM of the TCRT.

EDITED: @AllisonAmg

Start and Stop Text on Plots was reversed.!, sorry about that

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#### AllisonAmg

Joined May 18, 2020
71
hi Allison,
Update on the 4093 circuit when using TCRT5000 Sensor modules.
As per your PM test, the TCRT have been disconnected so that you can test the Manual switches, looks OK.

Let me know when the Manual test is working OK, will then try S1 and S2 inputs.

E
Footnote:
The TCRT sensor output is High when activated ie: inverted compared to the original IR sensor, which gave you unusable results.
Cap C2 is used to enable a Latch Reset at Power On
The components inside the boxed dashed line area are the SIM of the TCRT.

View attachment 210021
Morning Eric,

I have ordered the TCRT5000's and the 2N2222's when they arrive i can build the prototype, and i will let you have the results.

Thanks again for all your effort on this, it is really appreciated

Allison

#### ericgibbs

Joined Jan 29, 2010
17,150
hi A,
Added the Points, White LED operation.
Manual operation ONLY for S11 and S22.
E

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#### AnalogKid

Joined Aug 1, 2013
10,218
When you say "I have ordered the TCRT5000's ", did you order just the emitter/receiver device or complete modules? I see it listed both ways on the innergoogle.

ak

#### ericgibbs

Joined Jan 29, 2010
17,150
hi Analog,
In Allison's absence, she has ordered the built TCRT module, the output is High when activated.
E

#### AnalogKid

Joined Aug 1, 2013
10,218
Here is the schematic of the module. Except for the emitting diode current limit resistor value, this agrees with the online images of the components. To me, it looks like the output goes low when the beam is reflected.

ak

#### ericgibbs

Joined Jan 29, 2010
17,150
hi A,
On checking his Arduino program I see that he appears to be inverting the Analog voltage to Digital level..??
Do you have the schematic that you could post.?
If it Low when the IR beam beam is being reflected back and detected, the 2N2222'a are not required.
E

Update:
Looking online a number of schematics, claiming to be TCRT5000 modules, some show the PD input on the OPA NI and others on on the OPA INV inputs.?

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#### ericgibbs

Joined Jan 29, 2010
17,150
hi A,
From your schematic and the TCRT datasheet, the Output will go low for that circuit when a object reflects back into the detector.
E

#### Attachments

• 9.3 KB Views: 3

#### AnalogKid

Joined Aug 1, 2013
10,218
In a PM, I raised the idea of modifying the IR module to run on 12 V and eliminating the 7805 regulator, and she asked for the details. I've been wrestling with some computer issues, but here is a first pass at a combined assembly that uses a bare TCRT5000 instead of a pc board assembly. Since we know what they are driving, changing to an LM358 eliminates two pull up resistors.

I saw the complete mudules online for around $1, including shipping. There is no way that replicating the modules will cost less; its all about the build. Follow up question: where are the two trigger manual switches (SWX) located - near the IR sensors, near the control board, or somewhere else? ak Last edited: Thread Starter #### AllisonAmg Joined May 18, 2020 71 In a PM, I raised the idea of modifying the IR module to run on 12 V and eliminating the 7805 regulator, and she asked for the details. I've been wrestling with some computer issues, but here is a first pass at a combined assembly that uses a bare TCRT5000 instead of a pc board assembly. Since we know what they are driving, changing to an LM358 eliminates two pull up resistors. I saw the complete mudules online for around$1, including shipping. There is no way that replicating the modules will cost less; its all about the build.

ak
View attachment 210064
Hi,

thankyou for this, i have already ordered a few of the TCS5000 modules, but if i can get them to work as they should i will building the subseqent ones using the 'raw' components.
Allison

#### AnalogKid

Joined Aug 1, 2013
10,218
Follow up question: where are the two trigger manual switches (SWX) located - near the IR sensors, near the control board, or somewhere else?

ak

#### AllisonAmg

Joined May 18, 2020
71
Follow up question: where are the two trigger manual switches (SWX) located - near the IR sensors, near the control board, or somewhere else?

ak
Hi,

The switches will be located on the control panel, the other circuitry will be remote to the control panel, near the sensors / leds

Allison

#### AnalogKid

Joined Aug 1, 2013
10,218
I tend toward modular wiring rather than daisy-chaining or paralleling downstream. Functionally the switches operate in parallel with the photo-detectors, but that can be messy wiring that makes later troubleshooting difficult. For the 116 schematic, what about adding two pins to P5 and P6 so there is a 4-wire run to the sensor and an independent 2-wire run to the switch (or a 3-wire run to a switch pair)?

ak