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Light-Operated Internal Door Latch - Using this light-operated circuit, you can close or open the door of your room remotely from your bed. You just have to focus the torchlight on the light-dependent resistor of the...___ Electronics Projects for You Multiple Pulse Generator - I used this circuit to ring my doorbell rapidly three times when a car pulled into my driveway. R2 and C2 set the output frequency. Use a diode and resistor to change the duty cycle, if desired. R1 and C1 set the cycle time which sets the number of pulse __ Designed by Andrew R. Morris
Multi-Switch Doorbell with Indicators - Here’s the circuit of a multi-switch input musical doorbell (shown in Fig.1). The circuit is built around the popular and less expensive quad D-latch CD4042B (IC1).When switch S6 is pushed to...___ Electronics Projects for You
Next-Generation-Star-Trek Doorbell - In the Star Trek “Next Generation” TV series, the doorbell outside the private quarters of a crew member makes a particular “beep-boop” sound. The 3v battery powered circuit below tries to simulate this sound. The circuit uses one 74HCT74 dual D flip/flop . . . Hobby Circuit designed by Dave Johnson P.E.-October, 2001
Parasitic Power Supply - This circuit powered a remote doorbell transmitter when a passive IR sensor light was triggered. It had no noticeable effect on the sensor light performance. __ Designed by Andrew R. Morris
Parrot-Sounding AC Door Bell - Here is a mains-operated door-bell that produces parrot-like sweet voice without requiring any musical IC. The circuit is cheap and easy to construct. The AC mains is fed to the circuit...___ Electronics Projects for You
Postman Buddy + Wireless Doorbell - Go beyond wireless doorbells: a mini-central that tells you when a letter is waiting you in the mailbox and if someone rung your bell when you were not at home. Complete design including PCB. __ Designed by Projects & Ideas from Nutchip.com
Programmable Door- Bell with Flashing LEDs - IC1 (NE555) is used here as a clock generator. It is configured as an astable multivibrator whose frequency can be adjusted with the help of potmeter VR1. The clock pulses obtained...___ Electronics Projects for You
Remote Control using Wireless Doorbell - This circuit lets you wirelessly control an appliance from a remote place by using a wireless doorbell. The appliance is triggered by the signal from the transmitter of the wireless doorbell...___ Electronics Projects for You
Remote Doorbell Beeper - This circuit will activate a beeper alarm whenever the AC line voltage is less than 100vac. . . Circuit by David Johnson P.E.-July, 2006
Remote Doorbell Warning Switch - This circuit should only be used with the solenoid type chime doorbells, the electronic type that play tunes will not work here __ Contact: IQ Technologies
Remote Doorbell Warning Switch - This circuit should only be used with the solenoid type chime doorbells, the electronic type that play tunes will not work here. The hardest part for this circuit was the title. It is quite easy to miss the sound of a doorbell if you are watching TV , this circuit gets round the problem by providing a visual indication, i. e. a lamp __ Designed by Andy Collison
Ring your bell; light your light - 11/11/99 EDN-Desgin IdeasThe circuit in Figure 1 provIdeas a simple and inexpensive way to provide illumination for a dark doorway. Pressing the doorbell button momentarily rings the doorbell and turns on the porch light. The porch light remains on for approximately 25 sec and then turns off. This interval is long enough for a person to find his or her way when it's dark. __ Circuit Design by Dennis Eichenberg
Self-powered Fast Battery-Tester - Tests 1.5 to 15 Volt cells; Two-LED display, no power supply required __ Contact: Flavio Dellepiane, fladello @ tin.it
Simple Circuit fix adds door-chime repeater - 05/13/99 EDN-Design Ideas Electromechanical door chimes can enhance your home, but they are vulnerable to costly repair problems. A defective pushbutton switch or a careless visitor can maintain the chime in an energized state for a prolonged period, thereby damaging the chime. The circuit in Figure 1 prevents damage to the chime and improves the chime's effectiveness by repeating the chime strike for as long as the pushbutton remains depressed. The circuit controls both front and rear chimes. The heart of the circuit is timer IC2, which you configure as an astable multivibrator. The timing components, R1, R2, R3, and C3, provide the required pulse widths. __ Circuit Design by Dennis Eichenberg, Parma Heights, OH
Star Trek Doorbell - In the Star Trek “Next Generation” TV series, the doorbell outside the private quarters of a crew member makes a particular “beep-boop” sound. The 3v battery powered circuit below tries to simulate this sound. The circuit uses one 74HCT74 dual D flip/flop. . . Circuit by David A. Johnson P.E.-October, 2001
Star-Trek Next-Generation Doorbell - In the Star Trek “Next Generation” TV series, the doorbell outside the private quarters of a crew member makes a particular “beep-boop” sound. The 3v battery powered circuit below tries to simulate this sound. The circuit uses one 74HCT74 dual D flip/flop . . . Hobby Circuit designed by David A. Johnson P.E.-October, 2001
Three Flashing LED Doorbells - Battery Powered LED Circuits: These circuits combine a buzzer with one or more LED displays. When the push switch is operatedthe buzzer will sound and the LEDs will flash. When the switch is releasedthe buzzer will stopbut the LEDs will go on flashing for another 30 seconds or so. __ Designed by Ron J.
Tiny Door Guard with Alarm - This simple Door Chime protects the door and gives a loud Alarm tone when there is an attempt of theft. The circuit is too simple and battery operated. A Normally Closed (NC) reed switch and magnet is used to trigger the circuit. Alarm generator is the popular ROM IC UM 3561. This 8 pin IC has an inbuilt oscillator to generate __ Designed by D Mohankumar
Touch Alarm for Door Knob - I designed this hobby circuit many years ago and it seems be a very popular construction project. Many companies offer simple alarm devices for personal use in bedrooms or hotel rooms. A metal chain attached to a box holding the electronics is place . . . Hobby Circuit designed by David A. Johnson P.E.-May, 2000
Touch-Plate Doorbell - This touch-plate doorbell makes use of enhancement-mode MOSFETs forming part of CMOS
quad NAND gate CD4007B in conjunction with a detector and Darlington driver stage. IC CD4007B comprises a dual complementary pair...___ Electronics Projects for You
Two Tone Generator - This two-tone generator includes 3 ICs NE555 Astable Multivibrators. You can vary the duration of each tone by changing the 10k resistor or 100MF capacitor at IC1 or changing resistors and capacitors at IC1/2 for higher or lower tone. __ Designed by Andrew R. Morris
Two-tone doorbell using 555 timer - No circuit description, schematic only___ CdS Electronic
Universal Ding-Dong - One frequently finds gongs or chimes for sale in antique shops or Eastern markets. But supposing one would want to wire these to a pushbutton at the front door to create a ding-dong doorbell? How would this be done? Or consider, for a moment, more creative possibilities. How would one e. g. cause wine-glasses or African drums to resonate when a doorbell is pressed? The circuit shown in Fig.1 provides a mechanical means of striking two gongs or chimes in sequence -- one when the doorbell is pressed, the other when it is released. This it does by briefly activating two solenoids in __ Designed by Jospfh
Wireless Doorbell - Installing a doorbell in an existing building is a difficult task as it involves wiring that can look shabby if not concealed properly. Presented here is a circuit that does not...___ Electronics Projects for You
Wireless Doorbell - The transmitter circuit is made up of two building blocks, the 303MHz RF oscillator and the 32kHz crystal controlled oscillator. The 303MHz oscillator consists of a self-oscillating circuit made up of the coil. __ Contact: Collin Mitchell
You've Had Your Fun-Now Make a Doorbell - OK, you've shocked Aunt Martha and embarrassed your granny with your fiendish Secret Farter. Now turn it into a useful doorbell.___ SiliconChip |
