Collection Schematic

This is electronic suspension wiring diagram of 1998 Buick Park Avenue Ultra. Click the picture to download.

The timing in 555 IC Timer is a function of charging rate of the external capacitor. This schematic needs expensive capacitors with extremely low leakage. The components limit the time between pulse to around 20 minutes. We can connect both halves in tandem with a divide-by network in between to get longer time periods. Here is the schematic :

The first timer section operated in an oscillatory mode. The first timer period is 1/Fo.Then the “divide-by-N” network recieves this signal and will generate the output signal with period of N/Fo. The second half of the 555 is triggered by the output signal of “divide-by-N”. So, the total time is now a function of Fo and N.

Part List Circuit Project Description

The circuit was created for the purpose of providing timing capability to turn OFF the amplifier as it becomes idle a specified amount of time.

Terminology 7812 ”“ 3-terminal 1A positive voltage regulator with short circuit protection, thermal overload protection, output transistor safe operating area protection, output current up to 1A, and output voltages from 5V to 24VLM358 ”“ a dual operation amplifier consisting of two independent, high gain, internally frequency compensated op-amps which were designed specifically to operate from a single power supply over a wide range of voltages having advantages of eliminating the need for dual supplies, compatibility with all forms of logic, and power drain suitable for battery operation, and with features of low input offset voltage, large output voltage swing, and very low supply current drain4060 ”“ a 14-bit ripple counter with internal oscillator that has glitches which may occur in any logic gate systems connected to its outputs due to the slight delay before the later counter outputs respond to a clock pulseBC557 ”“ PNP general purpose transistors used for amplification and switching due to its low current and low voltage Circuit Explanation

Based on the values used in the circuit, it can cause an amplifier or any other device connected to this circuit to be turned OFF after a minimum of 15 minutes of non-occurrence of even a low level audio signal from its input. The device can be turned ON by pushing the SPST switch P1 to allow feeding on any equipment connected to the female mains socket SK1. The combination of IC2A and IC2B produces square audio input while amplifying and boosting the input signal. This process is being monitored by the yellow LED D4.

The ripple counter and oscillator IC3 restarts and resets its counting when LED D4 illuminates for a very short peak value. During this stage, the 10.5 V relay with SPST switch starts to operate while the two transistors Q1

This is a simple circuit of one hour timer device with an audible warning which can be operated using supply from a battery. This one hour timer circuit can be implemented as a parking meter timer.

How the circuit works:

This circuit works by using just two CMOS IC’s, a 4011 quad 2 input NAND gate, and a 4020 14-stage ripple binary counter. At switch on R2 and C2 give a brief reset pulse, that will make sure the output pin Q1 of the 4020 is high. Gates U1 and U2 form a simple astable R1 and C1 deciding the timing period. The tolerances of capacitors differ widely, so for extra control, you could possibly make use of a 470n capacitor for C1 and apply a fixed 3.3M resistor in series with a 250k preset for R1. A timing period of just lower than 1.76seconds is needed.

The output of the oscillator at U2 drives the input of the 14-stage ripple counter, U3. The outputs divide sequentially by two and the output signal is obtained from Q13, needing 2048 input pulses just before the signal is getting high.

Once the output Q13 goes high, the output sounder will come to be active. Gate U4 of the 4011 is utilized to “modulate” the output sounder. As U4 is also joined towards the output of U2, the output sounder will turn on and off at the same rate as the oscillator.