External Watchdog timer Circuit design for heavy duty industrial usage
Budget: $10 – $30 USD
I have to create a circuit design for an external watchdog timer using industrial duty components as per below mentioned specs.
i have a PLC which i can program to give a 24V DC digital Output (Reset Pulse) every 2 seconds or so(adjustable) which will reset the watchdog timer. The timer duration should be adjustable using a potentiometer of sort. Minimum 0.5 s to 3 secs variable. The watchdog timer will have a changeover NONC relay which will be connected to an emergency relay. If the PLC stops working for any reason whatsoever and the watchdog timer doesnt receive the reset pulse for a set duration then the watchdog timer relay will switch off which will in turn switch off the Emergency relay of the system.
You can refer to the attached datasheet of an Omron timer which i need exactly, but the supplier of this is taking a long lead time to supply so i am forced to design my own timer.
Refer the H3FA-B 24DC timer of Omron.
Please ensure that the components you use should be standard off the shelf components and NOT customized made to order parts. Also, the components should be from reputed make and not for DIY use and should be used in industrial duty products.
I would need the circuit diagram, gerber files and BOM ready for manufacturing.
i have a PLC which i can program to give a 24V DC digital Output (Reset Pulse) every 2 seconds or so(adjustable) which will reset the watchdog timer. The timer duration should be adjustable using a potentiometer of sort. Minimum 0.5 s to 3 secs variable. The watchdog timer will have a changeover NONC relay which will be connected to an emergency relay. If the PLC stops working for any reason whatsoever and the watchdog timer doesnt receive the reset pulse for a set duration then the watchdog timer relay will switch off which will in turn switch off the Emergency relay of the system.
You can refer to the attached datasheet of an Omron timer which i need exactly, but the supplier of this is taking a long lead time to supply so i am forced to design my own timer.
Refer the H3FA-B 24DC timer of Omron.
Please ensure that the components you use should be standard off the shelf components and NOT customized made to order parts. Also, the components should be from reputed make and not for DIY use and should be used in industrial duty products.
I would need the circuit diagram, gerber files and BOM ready for manufacturing.