CMOS Simple Touch Switch Circuit
Similar to the CMOS based Blow About-face additionally on this site, this transistor based blow about-face can actuate a amount artlessly by the user affecting a metal plate. It is advised to anon about-face a broadcast to acquiesce it to be acclimated with ample loads. As it uses alone a few frequently accessible transistors and a 12V supply, it is ideal for adverse environments area automated switches would be damaged. Using a latching broadcast and two of these circuits, a simple two pad "touch on/touch off" adjustment can be made.
# The blow pad can be best calmly fabricated by acid a baby aboveboard of PCB actual and again soldering on a distinct wire. Alternatively, article like a penny alert to a artificial abetment will do the job.
# As mentioned, a latching broadcast can be acclimated so that a cursory blow activates the broadcast and it charcoal active. To about-face off a latching relay, ability charge be interrupted. So a 2nd ambit with a accustomed broadcast can be acclimated to cut ability (use the NC contacts on the 2nd circuit). Placed ancillary by side, two blow pads anatomy an "on" and an "off" pad.
CMOS Simple Touch Switch Circuit Part List:
# The blow pad can be best calmly fabricated by acid a baby aboveboard of PCB actual and again soldering on a distinct wire. Alternatively, article like a penny alert to a artificial abetment will do the job.
# As mentioned, a latching broadcast can be acclimated so that a cursory blow activates the broadcast and it charcoal active. To about-face off a latching relay, ability charge be interrupted. So a 2nd ambit with a accustomed broadcast can be acclimated to cut ability (use the NC contacts on the 2nd circuit). Placed ancillary by side, two blow pads anatomy an "on" and an "off" pad.
CMOS Simple Touch Switch Circuit Part List:
| R1 | 1 | 10 Meg 1/4W Resistor | |
| R2 | 1 | 47K 1/4W Resistor | |
| R3 | 1 | 120k 1/4W Resistor | |
| R4 | 1 | 470 Ohm 1/4W Resistor | |
| C1 | 1 | 15uF Electrolytic Capacitor | |
| D1 | 1 | 1N4007 Silicon Rectifier Diode | |
| Q1 | 1 | 2N5458 N Channel Field Effect Transistor | |
| Q2 | 1 | 2N2222 NPN Transistor | 2N3904 |
| Q3 | 1 | 2N3906 PNP Transistor | |
| K1 | 1 | Relay w/12V Coil, Contacts To Suit Application | |
| MISC | 1 | Board, Wire, Small Metal Pad For Touch Pad |
