Well here’s a cool little cat detection and repellent device using a sprinkler
controller and some timer delay circuits.  I think there’s a lot of timer delay circuits, especially the 555
being used for a lot of these DIYs, but I think it would be easier to do with BASIC controllers…
OR you can probably just buy a ultrasonic rodent repellent for under 40 bucks.
But that would really take fun out of life if you could buy everything out of your life…

Wow, maybe I can merge my sprinkler system and motion sensing alarm system
to make an alarm system that deters using sprinklers…just an idea.

Well, I got bit by a wild cat before and had to go to the doctor for rabies, where I
didn’t get a shot because I said “F&*@ it” but I guess the cat didn’t have rabies since I am still alive…
(Yes, thank God I am still alive!)

Not too long ago I had seen a floodlight motion detector connected to a sprinkler to discourage deer and other animals from raiding a garden. I had recently installed a sprinkler system, so I purchased a wireless driveway alert system and put the two to work. To allow enough time for the sprinkler valve to open, build pressure, and activate the sprinkler head, he constructed a time-delay unit from an old standby 555 timer. It activates the sprinkler valve with ac power from the control for 10 to 12 seconds — allowing plenty of time to open and apply a good H2O dousing to varmints and wayward mailmen alike

via make

Watch this robotic chair re-build itself!

This Ruben’s Tube will mimik your music with sine wave fireworks…awesome!

Watch standing waves being seen as open flames…

via wohba

Here’s a cool diy on a DAC circuit to control a DC motor with your PC over the internet using Visual Basic Winsock.

The circuit that I chose for this assignment is the motor project. The DAC circuit will be used to control the speed of a DC motor. This can be done by creating a Visual Basic program to interface with the motor and the PC. The input from the client will be in decimal form (0 - 255) and these digital sequences will be converted into binary codes (analog form) by using the DAC (digital to analog converter). The output voltage to the motor has a range of 0 and +5 volts. Since 5 volts will not be enough to run the motor, the system will be amplified using a Power Op-Amp circuit that can give us a higher output voltage so that the motor will have enough power to run. To be able to remotely controlling the motor, the winsock component, (the pc as the server, user as client), will be added in the VB program. Other motor related hardwares can also be controlled over the internet using the same setup e.g. a fan. From this fundametal knowledge, one can improve the control of other complicated machines or systems remotely. This can save time, less work and more secure in some cases.

Here’s a cool circuit for making your blinking eyes on holloween using the 555 timer chip.
This chip is very useful for a lot of applications.

The eye blink circuit consists of a timer and light emitting diodes, which function as the eyes. The timer circuit for the blinking eyes is based on the 555 timer. Figure 1 illustrates the standard timer circuit. The resistors and capacitor on the left control the charge and discharge of the circuit, which runs the pulse rate and duty cycle of the timer. The values in Figure 1 were chosen for a eye blink rate of approximately a second or two and a duty cycle of 85%. This simulates the blinking rate of eyes. The variable resistor allows the eye blink rate to be adjusted.

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Lightning strobe for your Halloween projects or any scary shows!

via Make

Here’s a cool DIY circuit for those of you making party lights for your halloween show.

Here’s a cool car battery charger diagram.

This very simple circuit uses a transformer ,two diodes , a capacitor and an ammeter. To charge a battery just connect the + and - terminals of the circuit to the corresponding terminals of the battery. When the battery is not charged, the ammeter reading shows 1-3 amps. When the battery is fully charged the ammeter reads Zero or nearly zero, after which the battery should be removed from the charger.

via electronic-circuits-diagrams

I found some cool looking circuits at this website here’s one of them that
detect levels of water by shorting…kinda nifty~

This circuit not only indicates the amount of water present in the overhead tank but also gives an alarm when the tank is full. The circuit uses the widely available CD4066, bilateral switch CMOS IC to indicate the water level through LEDs. When the water is empty the wires in the tank are open circuited and the 180K resistors pulls the switch low hence opening the switch and LEDs are OFF. As the water starts filling up, first the wire in the tank connected to S1 and the + supply are shorted by water.

via electronic-circuits-diagrams.com