Flashing Mains Neon Lamp
Here is a Neon Flasher circuit (untested) for a user request at Circuits FAQ. This can be built into a switchboard or a gadget for indicating Live Power. D1-C1 form a simple half-wave rectifier,...
Interface ICL7135 Voltmeter to 89C52
This circuit is a Parallel interface between 89C52 of Atmel with 7135 of Intersil. With This circuit you can read analog data of both polarities. You can change the range scale with extra circuits,...
WorkBench Dual Power Supply
I will just explain part of this circuit. D9 and D10 provide a low cost -1.4 from -5 V. This is needed to reach near 0.00 for LM317 Min. setting. An LED also can...
RS485 Modbus – Wireless Interface
I am working on alarm systems and would like assistance in designing wireless link for the unit, ie sensors to control panel, control panel to monitoring station. I noticed most of the circuits available...
Analog Dial Amps-Volts-Ohms meter
This was designed, keeping in mind, that sometimes we have few components available and you could not carry your DMM somewhere, but you have to make some instrument for a quick need with what...
Millivolt Source for Calibration
I was looking for a simple MILLIVOLT SOURCE for ion electrode testing and came across your pdf schematic. This design would appear to fit my needs perfectly, but I have a couple minor questions...
Frequency Divider 74HCT4040
U1 7555 is a CMOS version of 555. The 555 here is in Astable Oscillator mode, C1 and C4 are decoupling capacitors 0.1uF value, ceramic disc. Mixed and Interface Circuits The output is around...
Display On Timer with 555
This is related to the earlier post. This was done to save battery power. The output of some equipment may be in the form of LED Annunciators In the Security Guard Monitor, an Array...
