I am working on a senior design project between my internship and school and could use some help.
Scope: Design a PCB that will control high voltage for a perforation sensor. Perforation sensor is used on plastic bagging machines to detect the bags. The high voltage will "arc" or ground when the perf and sensor line up. This sensor will provide important info to a PLC and ultimately the system does not work without this sensor.
Old: Current method uses an ac transformer to step 120/240vac to 2400vac, a PCB then filters this ac into dc, the PLC controls when the PCB releases the HV to the sensor, when the sensors grounds/arcs the HV returns to the PCB where it gets filtered out to signal the PLC. PCB-PLC is 24v system. This method is old and the original engineers are no longer around, this method is also expensive ($200) and is not reliable. When the PCB is not active, there is about a 300vdc leakage to the sensor.
New: I am working with the concept of automotive ignition systems to step up the voltage. This requires pulsing the dc in a square wave to energize and de-energize the coil. I am using a hobbyist coil I found on amazon to step up the voltage. As this is a prototype, I am trying to keep cost down while I am bread boarding, ideally I want develop a finished PCB for my project/production that will cost around 50$. I currently have a cell phone charger as a power supply, 5v-1A, feeding into my bread board. Using a BJT, 2n3904, and a push button to toggle the power to the circuit. After the BJT, it goes to the coil where the voltage rises to around 5kv. LEDs are placed in a couple spots to indicate the status of the board, power and HV. I am getting nice arcs but I am struggling with detecting this HV after it grounds. One of my professors recommend to use a hall-effect sensor as a means to detect the HV. I bought some A3144 sensors to test but they are not sensitive enough. I did find a honeywell product that has a iron core and magnet windings with a hall-effect sensor between the iron-core so the flux density is channeled right to the sensor. I like this idea as it provides isolation and insulation between the high and low voltage regions.
I would greatly appreciate a new set of eyes to look at this idea and offer some help. I have access to all kinds of electronics test/measurement equipment if I need to do further analysis of the prototype. Attached PDF is a basic schematic of my breadboard made on draftsight.
Thanks AAC community!
Scope: Design a PCB that will control high voltage for a perforation sensor. Perforation sensor is used on plastic bagging machines to detect the bags. The high voltage will "arc" or ground when the perf and sensor line up. This sensor will provide important info to a PLC and ultimately the system does not work without this sensor.
Old: Current method uses an ac transformer to step 120/240vac to 2400vac, a PCB then filters this ac into dc, the PLC controls when the PCB releases the HV to the sensor, when the sensors grounds/arcs the HV returns to the PCB where it gets filtered out to signal the PLC. PCB-PLC is 24v system. This method is old and the original engineers are no longer around, this method is also expensive ($200) and is not reliable. When the PCB is not active, there is about a 300vdc leakage to the sensor.
New: I am working with the concept of automotive ignition systems to step up the voltage. This requires pulsing the dc in a square wave to energize and de-energize the coil. I am using a hobbyist coil I found on amazon to step up the voltage. As this is a prototype, I am trying to keep cost down while I am bread boarding, ideally I want develop a finished PCB for my project/production that will cost around 50$. I currently have a cell phone charger as a power supply, 5v-1A, feeding into my bread board. Using a BJT, 2n3904, and a push button to toggle the power to the circuit. After the BJT, it goes to the coil where the voltage rises to around 5kv. LEDs are placed in a couple spots to indicate the status of the board, power and HV. I am getting nice arcs but I am struggling with detecting this HV after it grounds. One of my professors recommend to use a hall-effect sensor as a means to detect the HV. I bought some A3144 sensors to test but they are not sensitive enough. I did find a honeywell product that has a iron core and magnet windings with a hall-effect sensor between the iron-core so the flux density is channeled right to the sensor. I like this idea as it provides isolation and insulation between the high and low voltage regions.
I would greatly appreciate a new set of eyes to look at this idea and offer some help. I have access to all kinds of electronics test/measurement equipment if I need to do further analysis of the prototype. Attached PDF is a basic schematic of my breadboard made on draftsight.
Thanks AAC community!
