Logic Probe Kit
The following instructions will allow you to build a practical test tool for troubleshooting and analyzing digital and microcontroller circuits. The complete Assembly and Instruction Manual can be downloaded from the the following web link:Don's Projects
Bill of Materials
Here's the components needed to build the Logic Probe shown in the Bill of Materials (BOM) picture.
Logic Probe Circuit Schematic Diagram
Here's the circuit schematic diagram for the Logic Probe.
Adding Resistors
Add the 1K and 330/470 ohm resistors onto the pcb and solder.
Add the (2) Capacitors
Place the (2) 150nf (0.15uF) capacitors onto the pcb and solder.
Add Battery Clip, Battery, 7 Segment LED Display, and Hex Inverter IC
Add a 5V Voltage Regulator IC, (2) 14 Pin DIP sockets, the Hex Inverter IC and the 7 Segment LED display components onto the pcb and solder them.
Add the 9V Battery
Snap a 9V Battery to the battery clip. The Letter L should be displayed on the 7 Segment LED Display. Next soldered a red wire on the pcb where "Probe" is located. Last, soldered a black wire next to the black wire attached to the 9V Battery Clip. Now, the Logic Probe is ready to trouble or analyze digital or microcontroller circuits.