Please can anyone help I just finish building an encoder test box see links for circuit diagram. This test spec covers checking the presence of encoder signals on 5V TTL incremental encoders. A test box with an LED is use to indicate when each signal is high.
The test box also incorporates a circuit to make the encoder zero pulse more noticeable by making a light stay on longer (the REF light). This light will also work with 1V ptp incremental encoders.
The problem I’m having is the box is not functioning as expected to be precise the REF led, the REF led stays on all the time when connected to a 5V regulated supply, but the encoder test boxes previously built uses 4.5V batteries and the REF led stays off all the time except when it’s connected to an encoder and the required encoder positioning is achieved it then comes on to indicate the right encoder position has been achieved as expected this is how the box is meant to function see links. Also when connected to a 5V regulated supply when I touch the connector pins N or S on the box with my fingers the REF led goes off the same problem also happens when I touch the pins on the leds, the + and – pins on the box power socket, the base pin of the transistor also the metal wire used to connect the leds together, this problems occurs only when touching with my fingers. The REF led goes off when I connect the box to an encoder and comes back on when the encoder position required as been achieved as expected. The problem is when the box is not connected an encoder why is the REF led always on as stated before this doesn’t happen with the encoder test boxes using batteries.
Does the REF led stays on all the time when connected to a 5V regulated supply due to interference from the power supply or is it to do with the transistors. So can anyone pleas help I’m all out of ideas I’m willing to pay anyone who can sort this problem. Please refer to the link I’ve attached. Thanks
The test box also incorporates a circuit to make the encoder zero pulse more noticeable by making a light stay on longer (the REF light). This light will also work with 1V ptp incremental encoders.
The problem I’m having is the box is not functioning as expected to be precise the REF led, the REF led stays on all the time when connected to a 5V regulated supply, but the encoder test boxes previously built uses 4.5V batteries and the REF led stays off all the time except when it’s connected to an encoder and the required encoder positioning is achieved it then comes on to indicate the right encoder position has been achieved as expected this is how the box is meant to function see links. Also when connected to a 5V regulated supply when I touch the connector pins N or S on the box with my fingers the REF led goes off the same problem also happens when I touch the pins on the leds, the + and – pins on the box power socket, the base pin of the transistor also the metal wire used to connect the leds together, this problems occurs only when touching with my fingers. The REF led goes off when I connect the box to an encoder and comes back on when the encoder position required as been achieved as expected. The problem is when the box is not connected an encoder why is the REF led always on as stated before this doesn’t happen with the encoder test boxes using batteries.
Does the REF led stays on all the time when connected to a 5V regulated supply due to interference from the power supply or is it to do with the transistors. So can anyone pleas help I’m all out of ideas I’m willing to pay anyone who can sort this problem. Please refer to the link I’ve attached. Thanks
