Discrete components sound and light control stairs delay switch circuit 8

Description: A modified piezoelectric ceramic acoustic-electric transducer is utilized to create a sound and light control system for a stairway walkway with a delay lighting switch. The circuit structure is relatively simple, consisting of diodes VD1 to VD4 and a silicon-controlled rectifier (SCR) VT5, which manage the sound and light control delay lamp. The control loop involves components VT1 to VT4, which regulate the power supply. When the lamp is off, the circuit can output a steady voltage of 8.8V at terminal E. The light control circuit includes resistor R1 and transistor VT3, which operates under low resistance conditions. When the ambient light is low, VT3 conducts, causing an audio amplifier tube (VT1) to pull the collector low, preventing operation. The second transistor VT2 is biased to remain in an off state. The collector voltage for VT2 measures approximately 7.2V. Although the base resistance for VT1 is high, it is connected to the rectified output from diodes VD1 to VD4, allowing VT1 to conduct and keeping SCR VT5 off, preventing the light from illuminating. When someone walks on the stairs, their footsteps or voices are detected and converted into an electrical signal, which is amplified by VT4 and coupled to the base of VT2, turning it on. This action inverts the parallel emitter junction of VT1, creating reverse bias voltage, which allows VT1 to conduct, triggering SCR VT5 and lighting the lamp. The lamp remains lit due to the controlled supply voltage, even after the sound ceases. The circuit is designed to maintain a collector level of approximately 7.2V for VT2 when no sound is present. The delay time of the circuit is influenced by various factors, with a typical delay of about 50 seconds. The resistance values in the circuit can be adjusted to optimize performance.

The circuit design employs a piezoelectric ceramic transducer that detects sound vibrations, such as footsteps, and activates the lighting system accordingly. The primary components include diodes for rectification, SCR for switching, and transistors for signal amplification and control. The piezoelectric element generates a voltage when subjected to mechanical stress, which is then processed by the circuit.

Diodes VD1 to VD4 rectify the AC signal generated by the piezoelectric transducer, ensuring that the voltage is of the correct polarity for the subsequent components. The SCR (VT5) acts as a switch that allows current to flow to the lamp when triggered. The control loop, composed of transistors VT1 to VT4, manages the response of the system based on ambient light conditions and sound detection.

Transistor VT3 serves as a light detection mechanism; it conducts when the ambient light level is low, allowing the circuit to remain active. The audio amplifier (VT1) processes the signals received from the piezoelectric transducer. The collector of VT2 is designed to maintain a low voltage level when no sound is detected, ensuring that the system remains in a standby state until activated by sound.

The delay feature is an essential aspect of the design, preventing immediate response to transient sounds and allowing for a more controlled lighting experience. The delay is adjustable through specific resistor values, which can be fine-tuned to suit the environment and user preferences. Overall, this circuit provides an efficient and effective solution for automatic lighting in stairway walkways, enhancing safety and convenience. By using a modified piezoelectric ceramics ashamed acoustic-electric transducer sound, light twist stairs walkway delay delayed lighting switch, circuit structure was relativel y simple. Diode VDl - VD4, SCR VT5 composed sound and light control delay lamp abundance go the same way, the control loop is VT] -VT4 and other components of the composition, control the power supply from the River Road B buck, vs regulator spoon (j filtering group that, when the lamp is off E, c.i terminal can output straight stream T 7 operating voltage of 8.8V. control loop R1. and so on VT3 composed of light control circuit, the day was low resistance RL, VT3 conducting, audio amplifier tube Vl collector 4 pull clamp low blood level iLl, it can not work ashamed Second shake tube VT2 base resistance value R.

therefore, VT2 at large to approximate the off state, the collector of the higher fU measured as 7 2V.VT1 base resistance, although larger, but it is taken from the high pressure connection blind VDl- VD4 rectified, save VT1 conduction, product thyristor VT5 off, fU light E does not light. At this time, I NIE Rong (. Ran was filled with positive left negative charges, the potential difference of about 7V so. night .RT. showed a high resistance, VT3 deadline, lift the VT4 owl electrodes blockade, especially if the ambient noise, the circuit state does not occur t1 subject of.

If this time if someone walking on the stairs, B will pick people walking footsteps or voices, and converts it to a corresponding electrical signal after amplification VT4, from 0 coupled to the base of VT2, cho make VT2 conduction .C. VT2 by inverting the parallel VTi emitter junction, it becomes reverse bias charging voltage VT1, so make VT1 sectional it.

thyristor tube VT5 and opened by R. get trigger current, F lamp by light, after the lamp is lit, go the same way to control the supply voltage drops, even if the sound disappears, VT2 collector is still in the lower level, VT1 still under reverse bias of the cut-off, so the lamp can be maintained luminescent then C:. after R:, R and R. a discharge, the absolute value of the reverse bias voltage decreases, when closing time sufficient to maintain VTI, V11 conduction, VT5 lost when the trigger current AC.

zero crossing, that is turned off, the lamp E goes out. Bong circuit in addition to the voice sensitivity by amplifying Ji VT4 several effects, to a large extent by VT! operating state must be. R. resistance must be adjusted so that it is in a critical state off when that is no sound, its collector grant level in about 7 2V, so that when the base is slightly touched, namely flip is turned on delay time of the circuit by the collapse of many factors Movies ask about sound, icon data delay about 50s, such as undesirable, town to change ( 2 capacity Quine were gluttonous.

adjustment section R, the resistance can be adjusted from the light control circuit handles.