Hi Guys,
I am after a little help with a switching circuit. I understand it can be done simply with a transistor, and I can build the circuit once it is designed/drawn, but I am at a loss to find a circuit that does exactly what I need.
I can't provide a circuit of what I have, but I expect an explanation should suffice...
I am constructing a remote door sensor system for an Art Gallery for my brother-in-law, so that he can go inside the house of shed and know when someone enters the Gallery. We will use an IR Beam sensor from Jaycar, item: [http://www.jaycar.com.au/Access-Con...ators/Commercial-Grade-Doorway-Beam/p/LA5193] to detect the person entering, and I want to use the output from that to trigger a 433MHz transmitter / receiver [http://www.jaycar.com.au/PRODUCTS/K...Automation/433MHz-Remote-Switch-Kit/p/KC5473] to sound a piezo buzzer. The transmitter can be triggered by several means, such as the built-in push button switch, or a rising voltage spike of >2VDC, or the closing contacts of a switch.
The output of the IR Beam unit (on the side of the speaker) is via a 3.5mm stereo plug/socket, with terminals I will refer to as C, L and R (Common, Left and Right)
In the 'un-triggered' state of the IR Beam (ie; no person present to cut the beam) the voltages are as follows (using a 12V plugpack to power the IR Beam unit):
C to L = 11.5V
C to R = 5mV
L to R = 11.5V
When the IR Beam is triggered, the voltages are:
C to L = 11.5V with no obvious spike or change
C to R temporarily drops to 0V, then returns to 5mV
L to R temporarily drops to 0V, then returns to 11.5V
I'm not keen to measure the Ohms across C to L or L to R, but resistance across C to R is 36 ohms in the un-triggered state, and is open circuit whenever and while the IR Beam is cut (ie not momentary open circuit).
Could anyone provide a circuit that can either:
Many thanks in advance,
Ian
I am after a little help with a switching circuit. I understand it can be done simply with a transistor, and I can build the circuit once it is designed/drawn, but I am at a loss to find a circuit that does exactly what I need.
I can't provide a circuit of what I have, but I expect an explanation should suffice...
I am constructing a remote door sensor system for an Art Gallery for my brother-in-law, so that he can go inside the house of shed and know when someone enters the Gallery. We will use an IR Beam sensor from Jaycar, item: [http://www.jaycar.com.au/Access-Con...ators/Commercial-Grade-Doorway-Beam/p/LA5193] to detect the person entering, and I want to use the output from that to trigger a 433MHz transmitter / receiver [http://www.jaycar.com.au/PRODUCTS/K...Automation/433MHz-Remote-Switch-Kit/p/KC5473] to sound a piezo buzzer. The transmitter can be triggered by several means, such as the built-in push button switch, or a rising voltage spike of >2VDC, or the closing contacts of a switch.
The output of the IR Beam unit (on the side of the speaker) is via a 3.5mm stereo plug/socket, with terminals I will refer to as C, L and R (Common, Left and Right)
In the 'un-triggered' state of the IR Beam (ie; no person present to cut the beam) the voltages are as follows (using a 12V plugpack to power the IR Beam unit):
C to L = 11.5V
C to R = 5mV
L to R = 11.5V
When the IR Beam is triggered, the voltages are:
C to L = 11.5V with no obvious spike or change
C to R temporarily drops to 0V, then returns to 5mV
L to R temporarily drops to 0V, then returns to 11.5V
I'm not keen to measure the Ohms across C to L or L to R, but resistance across C to R is 36 ohms in the un-triggered state, and is open circuit whenever and while the IR Beam is cut (ie not momentary open circuit).
Could anyone provide a circuit that can either:
- swap the change from 36 ohms to open circuit to provide a positive closing switch action (which can be temporary/momentary as the normal push button switch on the transmitter board is a momentary contact switch), or
- provide a +ve voltage spike of > 2V from the temporary C to R drop to 0V.
Many thanks in advance,
Ian