Elektor Team (9510)

1-07-1989 | 033 VARIABLE LOW-PASS FILTER The Type SSM2045 lc from Pmi is an active low- pass filter whose order, Q-factor, cut-off frequency and amplifi...

1-07-1989 | 034 GENERAL INTEREST AUTOMATIC SWITCH Many battery-operated instruments, such as digital voltmeters, have a change-over on-off switch. The a...

1-07-1989 | 30V 1>5pA D1 le 3mm red Cl Tant. T 2p 16 O *see text ELEKTOR ELECTRONICS JULY 1989 SUPPLEMENT LOW DISSIPATION REGULATOR With the advent of t...

1-07-1989 | 24 036 TELECOMMUNICATIONS DUPLEX AUDIO LINK Duplex communication is, of course, not a new technique: it has been used, for instance, in tele...

1-07-1989 | 037 HEAD / TAIL LIGHTS FOR MODEL RAILWAY a DI D5 (•o The price of a model railway locomotive is directly proportion- al to its facilities...

1-07-1989 | 038 1/0-FRIENDLY KEYBOARD COMPUTERS Not all computers have a keyboard, yet it is often essential to have the use of one. Two circuits are pr...

1-07-1989 | P 1 R9 12V R4 039 ENERGY CONTROL FOR BATTERY CHARGERS R3 85 11 01C2 D2 D3IRef 1C1 rr= P2 T2 50k R6 R2 00 50k BC517 T1 2 ROR7 1% 9. 10* BC517...

1-07-1989 | 040 TEST & MEASUREMENT The Type LTC1042 lc from Linear Technology is a window comparator that can function with very small currents. This is...

1-07-1989 | 041 CAR ELECTRONICS The car alarm accepts signals from a variety of sources, includ- ing special sensors and the standard switches in a car,...

1-07-1989 | 042 This inexpensive unit switches the light on at dusk and off again at dawn. The circuit has separate time bases for the on and off delays...