A Low cost A/D with a Potential of 5KV Isolation from Computing elements by use of Normal/Special Opto-Couplers. This can give better resolution and accuracy than a 8 bit A/D. may be close to 10 bit A/D. Added advantage is that you can optically isolate the inputs.
Suppose your temperature sensor touches a heating element OR [...]
Archive of entries posted by dapj
Convert Analog to Digital with a V-F
Analog Op-Amp Tutors with Gadgets
I have made some iGoogle Gadgets with canvas view, these are analog opamp tutors. Interactive Tutorial with Simulated Meters and Potentiometers, demonstrating how Operational Amplifier functions in different configurations.
Op-Amp Simulation using Javascript
Inverting Amplifier Gadget – Get Inverting Op-Amp Tutorial
Non-Inverting Opamp Gadget – Get Non-Inverting Op-Amp Tutorial
Buffer Unity Gain Amp – Get Buffer Unity Gain Op-Amp [...]
Electronic DIY Projects from Dago
USB-to-1-wire Adapter, ALC-60X Argon Lasers, DDS Function Generator and Gainclone Stereo Amplifier.
Electronic DIY Projects from Dago
Make a temperature logger for your room on a PC, This uses DS1820 sensors from Maxim and USB for interfacing. USB to 1-wire adapter helps attaching sensors to the computer. This circuit also uses a MAX8881 – 12V, Ultra-Low-IQ, Low-Dropout [...]
Microohm Meter with LED Analog Bar
This indicates like LM3914 in dot-mode. It is a drawing i made made to troubleshoot a gadget, around two decades ago. Strangely it had a echo of a design i had made into a 7107 dpm years before that. Now i am scanning all my drawing and notes, useful or not. Clean or with errors. [...]
Two PCB Mills – Jonathan Ward and Ilan Moyer
Make your own PCB Mechanical Routing/Erosion/Milling Machine at a low cost.
PCB Mill – Jonathan Ward – MIT
“Design a low cost circuit board milling machine optimized to be mass-produced.”
Low Cost PCB Mill lan Moyer
The overall device has a working area of 4″ x 6″ with a footprint roughly the size of a letter-sized sheet of paper. [...]
Mains Powered China Emergency Bulb
A typical Mains Powered China Lamp. On power down, LED light turns on for around 1/2 hr. Gets damaged on lightning activity and wide (uS not nS) transients above 300V. Drawing may have error.
From Schoodles
Torch or Flashlight Circuit Improvements
I fixed a China Torch with New LEDs and a Diode, it failed probably on a drop shock, the battery wire cut … then when put on charge Few LEDs went bad, as battery was absent in ckt.
design review – 1.5uF voltage rating can increase like 440V AC. A current source with low dropout voltage [...]
LED Lamp – Simple Bed-Lamp Circuit
LED Night lamp, Clock Lamp to see time at night. It is a Green Lamp just 50mA, but its Blue in Color.
From Schoodles
This can be a first LED Lighting project anybody can do. Just twist wire, use insulation tape. Get a Nice Mains adapter that will provide 6V DC. 5V also will do. A prior [...]
Mains Adapter 230V AC 50 Hz to Rectified DC
Mains Adapter Converts 230V AC 50 Hz to Rectified DC which replaces a Battery Pack. It was also called Battery Eliminator by older generations as it was used to save Battery Cost in AM Radios.
From Schoodles
The most important product safety aspect is the transformer, may it be well isolated, may it use a split bobbin, [...]
Ni-Cd and Li-ion Battery charger Generic
This is a Generic charger that is made by many brands, the circuit is an approximation of all. Some improvements suggested. Some brands in europe and usa also use this circuit. This works well, but may not be in the best interest of battery life. The cost of the charger needs to be low. So [...]
LED Flashlight made out of a China Lamp
LED Flashlight made out of a China Lamp that was busted on a High voltage surge during a Thunderstorm.
From Schoodles
I got many LED lamps, mainly from china. The Chinese Entrepreneurs are Creative and Adventurous. There is a problem though, the quality, reliability and safety factors are not so good. These are so for even branded [...]
