Touch the manipulator of an electronic key

With the introduction of a Telegraph key iambic prefixes [1], I was faced with the difficulties of manufacturing Dvorakova manipulator, the quality of the execution of which depends on the clarity in the air. There is some inconvenience in the transition from Odnoralov manipulator. The idea of a trackpad already met in the pages of magazines "Radio", but practical schemes I have seen.

This manipulator (Fig. 1) works with electronic keys as TTL and CMOS strukturnih chips, with easy, and with the keys with iambic mode. Power supply voltage 3 - 15 V is supplied directly manipulated with the key. Current consumption - only mode press and is about 0.4 mA. Except CLA you can apply CLA, CLA connecting unused inputs with the power bus. -

Fig.1

The distance from the input circuits to the touch contact should be minimal. Touch the contacts are made of glass fibre laminate plates bonded in between a foil to the outside. On each alternate path leading to a common wire, and the track is connected to the inputs of the corresponding element (Fig.2). When a finger is the output of the element And does not change its state, transistor switch is triggered and transmitted series of digits. You should not do too narrow the distance between the tracks, as sweaty finger leaves the wet film and the key can give extra character until it evaporates.

Fig.2

When the touch manipulator was easier to work at high speeds, it requires no configuration and is suitable operators, prefer mild and severe stroke of the manipulator. Fans Odnoralov it allows manipulator to work in iambic mode.

Literature:

Inozemtsev Y., Iambic consoles to electronic keys. Radio,1990, No. 4, p. 32.

Author: A. Sizov (UA2FT), Kaliningrad oblast, the city of Polessk; Publication: N. Bolshakov, rf.atnn.ru