Fluid or Water Level Indicator
The Reed Relay based Float Switches are used in Automobiles and even corrosive and volatile fluids. This can also be used to indicate level of water or operate pumps. The reeds are hermetically sealed...
80C39 and MCS48 based Process Controller
The Early Microcontroller : 80C39 is a CMOS Version of 8048 the one that preceded 8031-8051. MCS48 is the set for that, MCS51 is the current set. Digital to Analog Converter with uC Watchdog...
Telephone status indicator with LED
This will monitor telephone status without loading the telephone line, this way if you have two phones in parallel you will know if one of them is busy. Connect the two ends of circuit...
Button and four LED Lights
Need a design – Simple one button push button to turn on 4 different LED (3mm Dome) every time you press the button. 555 Circuits, LED Schematic. User Interface Design. JE USA Attached is...
+5 to -5 using a 555 Astable Multivibrator
This is a very simple -5V supply using one 555, useful for analog blocks using FET Opamps using low power. This circuit came up when i had to design limited by inventory. It worked...
Analog and Digital Voltmeter using ICL7107
This Circuit is a DPM or digital panel meter. It has a analog bar graph display and a 3-1/2 digit digital display. ICL7107 is used in the 200mV configuration. U4A opamp LF353 amplifies the...
Voltage to Frequency Converter ICL8038
This circuit is alternative approach to same solution show in earlier post. Here i have put the complete circuit in PNG format. 8038 is a marvelous chip, a custom monolithic analog computation unit, a...
Electronic Fifteen LED Roulette
The following was submitted on July 11th, 2007. Message: I want to combine Ne555 with 74154 IC.The indication of the outputs must be shown with LED’s but up to so far it need 15...
