Fuse box with 6 monitored channels

From CaveLab
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This module was part of the rack box project — which was terminated when I moved out of my first apartment.
FB1 installed in the Rack box

FB1 has three 12V and 5V circuits, every circuit has fuses on both polarities and is monitored. Every pair of fuses supplies a optoisolator with positive and negative voltage. When both polarities are present the optoisolator will trigger the inverter. When the input of the inverter is triggered, the output will be inactive. If a fuse should break the optoisolator will cut the signal to the inverter, causing the output to be activated and a LED indicates which circuit is broken. All inverter outputs is connected to a OR gates that sends an alarm signal to Main monitoring unit.


Schematic drawing


Parts list

Qty. Part
2 × DIL socket, 16-pin, 7.62mm
2 × DIL socket, 6-pin, 7.62mm
6 × Diode, small signal, 1N4148/Ph
1 × Enclosure, plastic (1591 FL), 150x80x50mm, flange
5 × Fuse 5x20 mm, 200 mA, fast-acting
4 × Fuse 5x20 mm, 1 A, fast-acting
2 × Fuse 5x20 mm, 2 A, fast-acting
2 × Fuse 5x20 mm, 2.5 A, fast-acting
13 × Fuse holder, open, PCB, 5x20mm
13 × Fuse holder, open, PCB, Protective cover
1 × Hex inverter buffer/converter, 4009, 6 channels
6 × LED 5mm, Orange, 2.0V, 20mA
1 × LED 5mm, Yellow, 2.0V, 25mA
2 × Mounting bracket, DIN rail, Plastic
1 × Optocoupler, 4-channels, PC817
2 × Optocoupler, single, CNY17F-3, DIL-6
64 cm2 PCB, stripboard, 100x160mm, 160cm2
6 × Resistor, carbon film, 0.25W, 4.7 kΩ, 5%
6 × Resistor, carbon film, 0.5W, 8.2 kΩ, 5%
13 × Resistor, metal film, 0.6W, 1 kΩ, 1%
16 × Terminal block, screw, 2.5 mm
6 × Transistor, NPN, 100 mA, 45V, 0.5W, BC547B