| Category | No. | Description |
| Alarms | 98 | Alarms and security related electronic circuit diagrams / circuit schematics |
| Amplifiers | 84 | Audio power amplifier circuit diagrams / circuit schematics |
| Arduino | 54 | Arduino based circuit diagrams and general Arduino projects |
| Audio | 111 | Misc audio circuit diagrams / circuit schematics (also see Music, Amplifiers and Preamp circuits) |
| Automotive | 71 | Automotive, car and motorcycle electronic circuit diagrams / circuit schematics |
| Control | 119 | Motor and general control electronic circuit diagrams / circuit schematics |
| Data Acquisition | 44 | Data acquisition (DAQ) and data logging circuit diagrams / circuit schematics |
| Filter | 45 | Electronic filter circuit diagrams / circuit schematics |
| Games | 76 | Games and fun stuff (electronic circuit diagrams / projects) |
| IR | 69 | Infrared based electronic circuit diagrams / circuit schematics |
| Laser | 43 | LASER related power supplies and data transmission circuit diagrams / circuit schematics |
| LED | 99 | LED related electronic circuit diagrams / circuit schematics |
| Lighting | 51 | Lighting and light controller electronic circuit diagrams / circuit schematics |
| Medical | 32 | Medical and health related electronic circuit diagrams / circuit schematics |
| Metal | 37 | Metal detector circuit diagrams and projects |
| Microcontroller | 133 | Microcontroller based electronic circuit diagrams / circuit schematics (also see Programmers) |
| Misc | 225 | Miscellaneous electronic circuit diagrams / circuit schematics |
| Models | 91 | Models, remote control toys, robotics related electronic circuit diagrams / circuit schematics |
| Music | 84 | Music related electronic circuit diagrams / circuit schematics (also see Audio) |
| PC | 116 | PC (personal computer) related electronic circuit diagrams / circuit schematics |
| PDA | 20 | Smartphone / PDA / MP3 music player interface circuit diagrams / circuit schematics |
| Photo | 42 | Photography related electronic circuits and electronic projects |
| Power | 164 | Power supply and power control circuit diagrams / circuit schematics |
| Preamp | 43 | Audio preamp circuit diagrams / circuit schematics |
| Programmers | 21 | Circuit diagrams and construction details for microcontroller programmers |
| RF | 187 | Radio-frequency RF circuit diagrams (also see RF Amplifier and Transmitter circuit diagrams) |
| RF_Amplifier | 32 | RF (radio frequency) amplifier circuit schematics (also see RF and Transmitter circuit diagrams) |
| Solar | 39 | Solar-power electronic circuits and electronic projects |
| Telephone | 74 | Telephone and intercom related electronic circuits and electronic projects |
| Test | 194 | Test equipment circuit diagrams and electronic projects |
| Timing | 79 | Timing and oscillator circuit diagrams / circuit schematics |
| Transmitters | 94 | Transmitter circuit schematics includding bugging device circuits (also see RF circuit diagrams) |
| Tube | 42 | Vacuum tube / valve, VFD and nixie tube based circuits and projects |
| Video | 69 | Video related circuit schematics / circuit diagrams including video transmitter circuits |