What is NPN open-collector output?
An Open Collector output is an NPN transistor. An NPN transistor allows the sinking of current to common. It can be thought of as a switch that allows the circuit, after the load, to be connected to common. The voltage should be measured across the output load to determine if the open collector is working properly.
How do you wire an open-collector output?
To do this, connect an open collector digital output to the control terminal of the relay board, with a 10kΩ resistor pulling the line up to +5V. This way, the relay will be constantly powered until the open collector digital output is switched on, which will then cause the control line to become grounded.
What does an open collector do?
Open-collector devices are commonly used to connect multiple devices to one interrupt request signal or a shared bus such as I²C. This enables one device to drive the bus without interference from the other inactive devices.
What is IC output?
In the picture, the transistor base is labeled “IC output”. This is a signal from the internal IC logic to the transistor. This signal controls the transistor switching. The external output is the transistor collector; the transistor forms an interface between the internal IC logic and parts external to the IC.
How does a NPN sensor work with a PNP sensor?
NPN outputs work the other way around. When the sensor is active, it puts into contact the output wire with ground. Which means that it doesn’t inject current in the output wire. Therefore, for the change to be detected, someone has to put some voltage on the wire. It’s the job of a pull-up.
Where can I find NPN and PNP outputs?
This type of NPN or PNP output is widespread in the industrial world. It’s used for example in proximity sensors, but you can also find them in more exotic sensors such as bubble sensors. These outputs provide binary (ON/OFF) information, and not an analogical value. You therefore find them mostly in detectors rather than in measuring devices.
Can a Yocto-PWM-RX read a NPN output?
The Yocto-PWM-Rx can also read an NPN or PNP output. It measures a 0% duty-cycle when the input is zero and a 100% duty-cycle when the input is 1. It even has a pulse counter enabling to precisely count the number of transitions happening in a given time frame. It can count tens of thousands transitions par second.
How does NPN work with a power supply?
The voltage on the signal wire therefore changes to the value of the power supply voltage. It has the advantage of being very simple, but you can’t really choose the signal output voltage. NPN outputs work the other way around.