Circuits / Electronic Circuit Diagrams

Low Cost AM FM Stereo Receiver

(delabs) — Mon, 16 May 2022 11:29:00 +0000

FM stereo demodulation is accomplished by the use of the LM1800 phase locked loop, thereby eliminating the need for external coils. The AM function of the receiver is done completely with the LM3820 AM radio system. While designed for 3 section tuned superheterodyne application.The LM382 dual preamplifier was selected for its minimum parts count and low noise capability.

DMM with ICL7103A and ICL8052A

(delabs) — Tue, 02 Nov 2021 04:05:00 +0000

The purpose of this application note is to describe the operation and potential pitfalls of a 10V resolution (VREF = 100mV) 4 1/2 digit autoranging scheme using the ICL7103A/ICL8052A pair. Two auto-ranging circuits are included within the text. Each is discussed in terms of its advantages and disadvantages.

Battery Operated Auto Ranging DVM

(delabs) — Mon, 01 Nov 2021 06:10:00 +0000

This application note describes a technique for auto-ranging a battery operated DVM suitable for panel meter applications. Also, circuit ideas will be presented for conductance and resistance measurement, 9V battery and 5V supply operations, and current measurement.

ATmega328 Single Board Computer SBC

(delabs) — Sat, 23 Oct 2021 09:05:00 +0000

The Atmel 8-bit AVR RISC-based microcontroller combines 32 KB ISP flash memory with read-while-write capabilities, 1 KB EEPROM, 2 KB SRAM, 23 general-purpose I/O lines, 32 general-purpose working registers, 3 flexible timer/counters with compare modes, internal and external interrupts, serial programmable USART, a byte-oriented 2-wire serial interface, SPI serial port, 6-channel 10-bit A/D converter...

Analog Blind Dial On Delay Timer

(delabs) — Fri, 12 Jul 2019 10:02:00 +0000

It is called analog dial timer as it has no digital display, but the chip is digital it is CD4541. It is Mains operated, you could make on-delay or off-delay. By changing the caps and resistors or with even dip-switches you could get timing of few seconds to many hours.

Battery Level Indicator

(delabs) — Thu, 11 Jul 2019 10:44:00 +0000

Battery level voltage measurement is best done with a dummy load. This circuit has four LEDs to show the charge left. It is important to avoid overcharge or deep discharge of rechargeable batteries. Never try recharging normal batteries. Using rechargeable batteries are good for the environment.

Sample and Hold with CD4066

(delabs) — Fri, 14 Jun 2019 09:17:00 +0000

A sample and hold is like an analog memory. If The digital control A is low 4066 switch is open, and when A is high switch is closed. U2B is a buffer so as to ensure quick charging of C1 thru 4066 on resistance of 100E. U2A is a FET input opamp buffer which does not load or drain the cap C1.