The second half controls the steering. The mechanical design is a 3 wheeled caddy with the ´single wheel´ actually a closely spaced pair of wheels which are driven by the main drive motor top provide motive power (this is the motor controlled by the first circuit). However the pair are on a motorised swivel arrangement: this second motor is the steering and can rotate the pair through 180 degrees, thus providing not only the steering but also the direction control.
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Tr3 and Tr4 are a current source feeding a 9v1 zener to provide the internal supply. Tr5 with the 6v2 zener supply a 5.6 volt supply to the radio control receiver. This receiver gives two outputs - one is used for motor speed control and the other is used for the steering.
Tr13 and 14 are a level shifter and pulse conditioner to shape the radio receiver´s output pulse. The shaped pulse is fed to the pulse length detector consisting of the first 555 with Tr15 and Tr16. The 555 (which provides a reference pulse) is triggered by Tr6 on the positive edge of the input pulse. Tr15´s collector is high only when the input pulse is present and the 555 if off, so it gives a pulse output only if the input pulse length is longer than the reference pulse. Similarly Tr16´s collector is high only when the refernce pulse is present but there is nothing on the input pulse. This pulse indicates reference is longer than the input.
Tr10 and Tr11 are a ´pump and hold´ circuit. Tr11 is operating at 90 microamps (9v, 100K) maximum so its base current is around 1/3 microamp (assuming a gain around 250). This base current is supplied via the 3M3 resistor (which is actually feeding 3 microamps - more than enough).
So under worst case conditions Tr10 might have an emitter current of 3 microamps. Its base current is around 10 nano-amps. Assuming Tr9 and Tr18 are not conducting, this base current can only come from leakage - or the 470n...
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....
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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.....
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