If you have a power source which will provide 2. 5Vdc at 10uA this circuit should drive a pager motor. It turns on the motor at 2. 3 to 2. 5Vdc and switches off at 1. 2 to 1. 5Vdc. Both Steve and I have built ( bread boarded or haywired) the business end of the design and achieved similar results. This does not mean that it will work for everyone but it should. [I used a BC559C (Q1), a BC549C
Click here to download the full size of the above Circuit.
(Q2) a BC559B (Q3) and a BC337-25 (Q4), which happened to be in the bitbox. SB] Enable power to the circuit. If the circuit works properly, the voltage will rise to a firing point, turn on the motor momentarily which discharges the capacitor to level where motor has little current passing through it but Q1 and Q2 are still conducting. At this point, . In practice, I removed R1, measured its value and replaced it with a standard resistor value 5 to 10% less. 560K was the value that both Steve and I used which shows just how repeatable this design is or how lucky we were. Note: It is realized that this presentation is very cryptic. If it were delayed until a complete circuit description and circuit layout were complete, it may not have been presented at all. It is hard for many to realize the time and effort it takes to create the circuit cards, obtain the correct parts, make up the kits and write assembly / debug instructions. The dollar cost and other risks are not minimal. The first results from building a number of units. It was found that R1 could be replaced with a 680K resistor rather than using a pot. R6 was added to limit the current used to drive the base of Q4 which meant that more current became available for the motor. 390 Ohms is the smallest value that should be used for R6, it can be larger depending upon the motor and drive transistor (Q4) combination. There is one further proposed change that could improve...
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: