| The circuit detects a change in video information and uses this to switch on an alarm in a closed-circuit television guard system of a vi...
All items tagged with PDF and Time (297)
| It is often not possible to put a second bell in parallel to the existing one, because the bell transformer is normally already fully loa...
| The lamp in slide projectors is normally controlled with the aid of a triac in series with it. This method reduces the brightness of the...
| Nickel-metal-hybride (NiMH) batteries have now become widely available. A typical one is the 120AAH, which has a capacity of 1.2 Ah in si...
| Many battery-operated appliances have an LED indicator that shows the state of the battery. If the battery is almost flat, the LED flickers....
| A simple unit for testing an audio, TTL or CMOS circuit is always useful. Here, an oscillator, based on IC(1a), generates a frequency tha...
| The UAA2016 from Motorola lends itself admirably to making a proportional mains-operated temperature control. A resistor with negative tem...
| The tester cannot only detect rectangular-wave signals. It can also generate them. The test signals may be generated continuously or for a...
| Based on only two ICs and a transistor, this circuit can perform three test functions selected by switch S1.
| This audio-frequency receiver is the counterpart of the infra-red transmitter. The output from the infra-red diode D1 is amplified by IC1...