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Programmable Digital Timer
Here is is gadget GUI for Industrial Process control, WebApps. The buttons make a sound and Light up internal LED lamps. Power On-Off control, Digital Timer; Start, Reset Scroll and Select are the controls. A Web Gadget which is a Preset Timer. This can be Programmed from any Browser. It can also be modified to control external outputs. The advantage is that the industrial process or Home automation can be monitored and controlled on any computer including tablets which has a Browser
Tristate Electronic Random Toss
Running LED, Random Results, Decade Counter and Clock. Weigh the Pros-n-Cons, Take a Balanced Decision. This can be built with one 555 timer and a CD4017. Use the pin 5 to connect to a cap you charge with a pushbutton or gate like CD4093 to turn off 555 using pin 4 after a cap discharges. This may simulate a random. Running LED, Random Results, Decade Counter and Clock. Weigh the Pros-n-Cons, Take a Balanced Decision.
Simple Hourglass Clock
Simple Hourglass Clock, Track Time Progress, Shows Time, Date, Weekday and Week of Year. Time flies but the Hourglass Clock helps you keep a watch on the endless flow of time. This fights procrastination, then the project will be done in time. There Aint No time left, Act Now. Finish the Box.
Audio Visual Metronome
A Metronome is any device that produces a regulated audible and/or visual pulse, usually used to establish a steady beat, or tempo, measured in beats-per-minute (BPM) for the performance of musical compositions. It is an invaluable practice tool for musicians that goes back hundreds of years.This is a Beat Box Gadget, Music Companion, Set Sequence of Sounds, Set Tempo and Play a Rhythm. Switch On/Off drums, Set the Tempo, Delay and Volume Sliders. Press Play.
RocketCake WYSIWYG Website Maker
RocketCake is a free web editor for creating responsive websites. For beginners and professional web developers. WYSIWYG Editor Edits the website as it appears on your device. Switch at any time to view and editor it as on any other tablet, PC or mobile. "Responsive" is just a fancy word for "adjusting to the screen size". Since people are viewing websites with different devices
grepWin search and replace
grepWin is a simple search and replace tool which can use regular expressions to do its job. This allows to do much more powerful searches and replaces. replacing strings is not more complicated than searching. Whatever the search finds is replaced with the replace string. Searching for cat and replacing it with dog is the most basic example and works just like you'd expect.
Universal Signal Conditioning
Here is a practical application of the dual differential amp. This circuit is for DC or slow moving DC like Strain Gauge and transducer signals. The RC and Zeners are for protection and clamping. Why and how has been described in other posts here. The high impedance op-amp input cannot face the real world unprotected. OP07 is always the selection due to the low offset. When the sensor generates data in mV, you cannot afford any error introduced in this front end, right.
LM331 A to D Mux Input Switch
This is the full circuit of a V/F convertor interface for 80C31 SBC. The Mux is configured for selecting between two inputs. It uses analog switch 4066. LF353 along with LM331 form the VCO, you can further study such configuration in the Application Notes of TI/NS.
Two Stage Sequential Timer
This is an example of a cascaded or sequential timer, here two CD4541 are forming a two stage timer. You can add more in a chain, but better to use a microprocessor or Microcontroller for such a purpose. But make sure EMI-RFI immunity is high for these circuits or wrong resets and sets can make a machine like an Oven or Environment Chamber malfunction and even ruin the job.
Analog Blind Dial On Delay Timer
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
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.
16 Channel Analog Multiplexer
This circuit is built around the chip CD4067, now called 74HC4067, it works like a single pole 16 throw rotary switch that can be controlled digitally. Clamping protection diodes are built in. Use resistors to enable this protection. 16 Analog channels are controlled by a Digital User Interface circuit made of 4093 and 4029. Up/Down and Auto/Man are four Push-buttons. A LED Display to show the Channel Number that is selected.
Synchronized Sample and Hold
This circuit has two analog mux 4051 operating in synchrony to store an analog value in a low leakage tantalum capacitor. This makes an Analog Memory possible and overall system accuracy of around 2%, which was more than adequate for this process. The analog value from a temperature transmitter is available for a short duration when it is collected from a rotating system with copper brushes and contacts on the shaft.
Digital Control for Analog Mux
A single Voltmeter or Digital Panel Meter DPM can monitor 8 Analog inputs from sensors or potentiometers using a Mux chip and creating simple digital controls for that. Four pushbuttons on the front panel control the scanner. One 4051 is used to multiplex 8 trimpots that hold the Analog Alarm Settings. The channel number in BCD is translated to a LED channel Display with a 4511 chip.
Timer and Counter Module
A digital counter monitors the number of times a process goes beyond a certain temperature limit over a long cycle of time. This circuit has a Analog Timer and Digital Counter. The Analog timer turns on an Alarm if the Temperature Limit transition is very long. U1 CD4541 is a Timer with Long Duration Ability. This timer is started by a low pulse from earlier circuit, when the temperature goes above setpoint, a low state is at U2A inputs, this starts the timer.
Pt-100 RTD Four Point Alarm
Four points in a Closed Loop Temperature Control System is Monitored and a Alarm set to go off when the temperature goes beyond the set limit. Here 4052 is used as an analog multiplexer, U3A TL062 opamp is wired as a 1mA Constant Current Source. It pumps 1mA into U2 4052 pin 13 X . Depending on BCD code on inputs A, B of 4052.
Sample and Hold with CD4066
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.