NE555-based telephone recording additional circuit

NE555 is one of the 555 series timing ICs. The pin function and application of the 555 series IC are compatible, but the different models have different stability, power saving and oscillation frequency. It's not the same; the 555 is a very versatile and fairly versatile timing IC that requires only a few resistors and capacitors to generate the pulse signals of the various frequencies required by the digital circuitry.
The characteristics of NE555 are as follows: 1. A simple resistor and capacitor can be used to complete a specific oscillation delay. The delay range is extremely wide and can range from a few microseconds to a few hours. 2. It has a large operating power range, and can be matched with logic gates such as TTL and CMOS, that is, its output level and input trigger level can be combined with the high and low states of these logic series. 3. The output current of the output terminal is large, which can directly push a variety of automatically controlled loads. 4. It has high timing accuracy, good temperature stability and low price.

Telephone recording additional circuit diagram