Having a very healthy population of moles in our vicinity, I logged onto eBay and bought four of the cheaply available (ultra )sonic mole deterrents for our garden lawns in the hope of persuading them to move elsewhere. Here`s a link to a couple of similar ads: eBay ad, eBay ad2. The basic idea is pretty simple and used with other animals too
Click here to download the full size of the above Circuit.
the gadget emits an frequency that the animals in question (in this case the moles) aren`t keen on, so they move away from the area. Some are advertised as being ultrasonic mole deterrent , and some simply say sonic mole deterrent . Are they sonic or ultrasonic (ultrasonic means above the range of human hearing of which the upper limit is around 20kHz) What frequency do they actually work at Unfortunately the particular model purchased didn`t work for long enough (see below) to answer this question fully, but I`d say they did seem to make a difference initially. Further tests will have to be made on this front. Note that 2N2222 and 2N907 are used in the SPICE circuit as LTSpice doesn`t have models for 9014 or S8550, which are the actual parts used on the PCB. This matters little to the simulation (see below) as the circuit should work fine with most general purpose bipolar transistors. Q1 and Q3 are responsible for the on/off pulses. If we start with Q1 turned on (via current through R1 into base), Q3 turned off, and either side of C1 at around 0V. R7 gradually charges up the right side of C1 (Q3b) until the voltage reaches around 500mV at which point Q3 will begin to turn on. When Q3 starts to turn on, Q4 and Q2 (BUZ_V) will also begin to turn on, activating the buzzer. Also the bottom of C2 will be pulled to ground, which will also pull Q1s base (Q1b) low, turning it off this will raise the voltage on the left (Q1c)...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
characters left: