# Infrared Beam Sensor

Joined Feb 4, 2022
127

#### bertus

Joined Apr 5, 2008
21,903
Hello,

Did you see this on the page?

Switching Output : Relays
Contact Output : NC/NO
Switching Frequency : 54 Hz

I wonder how long the relays may work at 54 Hz.

Did you also have a look at the "datasheet"?

Bertus

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#### BobTPH

Joined Jun 5, 2013
4,952
The relay allows you to switch a voltage of your choosing.

Bob

Joined Feb 4, 2022
127
Hello,

Did you see this on the page?

Switching Output : Relays
Contact Output : NC/NO
Switching Frequency : 54 Hz

I wonder how long the relays may work at 54 Hz.
i don't understand what you mean. What can happen if the switching frequency is 54Hz?

Joined Feb 4, 2022
127
The relay allows you to switch a voltage of your choosing.
We have three options relay, voltage divider and optocoupler so I just want to know what will be the best of these three

Joined Jul 18, 2013
25,233
i don't understand what you mean. What can happen if the switching frequency is 54Hz?
That is the carrier freq of the signal not the operating freq of the relays. Possibly meant to be 54 Khz?
The output is N.O. or N.C. contact.

Joined Feb 4, 2022
127
The output is N.O. or N.C. contact.
I don't understand following line in datasheet posted by @bertus

"Alarm output-General: Normally closed and normally open (NC&NO) Contact
capacity AV/DC 30V/0.5mA"

#### ericgibbs

Joined Jan 29, 2010
15,550
It means this, ref image.
E

#### BobTPH

Joined Jun 5, 2013
4,952
The output is a relay, i.e. it is a SPST switch. There is no voltage supplied to the output by the device. You connect a voltage to the common terminal, that voltage appears on the NC terminal when not activated and the NO terminal when activated. No need for an optocoupler since it is already isolated.

Bob

Joined Jul 18, 2013
25,233
IOW, as described, the C(om) and either the N.O. or the N.C. can be connected directly to an input on your Micro.
The input of which would normally be pulled up to 5v or switched, pulled down, to micro common supply.

Joined Feb 4, 2022
127
As given in the datesheet, it can activate for minimum 12V DC - maximum 24V DC

In datasheet My question is, will it activate on the 5V DC?

#### MisterBill2

Joined Jan 23, 2018
11,948
That is quite a bunch of words that the link in post #1 connects to. But they do not make much sense, or have much meaning. In fact the description is sort of meaningless propaganda, typical of the disreputable sales organizations.

But now if the TS does not understand about normally open contacts or about relays I predict not much success. Relay contacts feeding a digital input should work, but not understanding what "relay contacts" means tells me no it will not work.

#### ericgibbs

Joined Jan 29, 2010
15,550
Bill,
I don't know what you are reading, but the datasheet @bertus posted is easy enough to follow.

E

Joined Jul 18, 2013
25,233
As given in the datesheet, it can activate for minimum 12V DC - maximum 24V DC

In datasheet My question is, will it activate on the 5V DC?
The unit requires 12vdc at least to operate
It will be separate from the 5v required for the micro.

#### BobTPH

Joined Jun 5, 2013
4,952
Do you know what a relay does?

Bob

#### MisterBill2

Joined Jan 23, 2018
11,948
Bill,
I don't know what you are reading, but the datasheet @bertus posted is easy enough to follow.

E
I was referencing the link in post #1, NOT the data sheet that Bertus linked. I very clearly state that!

Joined Jan 15, 2015
6,593
A little tricky. Looking at the receiver it uses dry contact relay out but while they mention Form C it really isn't. This is what you have from the manual:

The receiver only has a Com and Out terminal. Connect the com to +5 Volts, use a pull up or pull down at your uC input. Some uC digital inputs van be programmed for Internal pull up eliminating the need for an external pull up resistor. In the above the com is tied low to ground so the out is switched low when active.

Ron

#### MisterBill2

Joined Jan 23, 2018
11,948
Referencing the circuit in post#17, I wonder if that "COM" terminal is tied to other than the relay contact common. Why else would the assembly have the two supply terminals AND a common terminal??

Joined Feb 4, 2022
127
The receiver only has a Com and Out terminal. Connect the com to +5 Volts, use a pull up or pull down at your uC input. Some uC digital inputs van be programmed for Internal pull up eliminating the need for an external pull up resistor. In the above the com is tied low to ground so the out is switched low when active.

Ron
Hi Ron,

According to what you said, the connection looks like this,

but I do not understand how to add pull up resistor in diagram

#### BobTPH

Joined Jun 5, 2013
4,952
The OUT terminal should go directly to the MCU pin snd the 10K should be between that connection and ground. That makes it a pull down resistor, which keep the MCU input low when the relay contact is open.

Bob