four position touch dimmer

N I four position touch dimmer 1111141110000 Any electric light may be adjusted with this dimmer to very low, low, medium and maximum, which in most cases will be sufficient. After all, it is all very well to be able to control an electric light over the whole range of its brightness, but how often is that facility really used? Moreover, in every- day use, position control has practical advantages: setting, for instance, takes a second or two. The circuit is based on an LS7237 and some discrete components. The dim- mer may also be used as an electronic on/off switch, in which case the mode select pin (7) must be connected to earth (pin 1). Such a switch does not produce sparks and consequent noise in nearby electronic equipment. C6 IMO R4 TIC 206D/ 226D 7-50 R5 TIC 206D/ 226D Ll 408H // Al A2 G 1N4148 220 „ 400 V 85444 Al elektor july/august 1985 Another possibility is leaving pin 2 open, whereby a three position dim- mer ensues: low, medium, and maximum. The LS7237 has all th...