A Mini Payphone Controller in order to use coins in three slot pay telephones
Posted on Feb 6, 2014
Related Circuits
New Circuits
-
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.....
.
This amplifier is so high quality that it would be understatement to speak HIFI amplifier....
The Tutorial shows how to interface 7-segment display to a microcontroller. Also explains how do...
It`s one of the simplest circuits to get working but one of the more tricky to understand. This...
The circuit below will trickle charge a four cell pack of AA or AAA NiMH batteries. The circuit...
This 1000 watt power inverter circuit diagram based on MOSFET RF50N06. If you want more power...
This stereo balance indicator circuit diagram is designed using few common external components....
Most ohmmeters of the design shown in the previous section utilize a battery of relatively low...
In the forward inverter system applications: IRZ110 for receiving such a line when the line shown...
200W lamp switch control, power supply voltage is 220V, is about 100lx illumination light...
Figure 289 Star STMicroelectronics (ST) deputy public cattle produced VK05CIl. ASIC production of...
characters left: