A cure that we are testing is to prevent the over voltage getting to the irreplaceable IC U5 - A1752CF after either the switch drives or returns are hit with either a static electric shock or the 24VDC solenoid bus. The protection is simple, there needs to be clamping diodes inserted in the circuit. These can be placed across the resistors R65 - R
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72 with the band of the diode (1N4002 or higher) soldered to the +5VDC end of the resistor and the non-band end to the other side of the resistor. Then on Resistors R57 - R62, connect the non-banded end of the diodes (1N4002. ) to the junction of the resistor and the trace leading to the IC and the banded end to a convenient +5VDC bus tie point. The (-12VDC) is the negative bus rail, and the (+5VDC) is the +5 bus rail. The -|>|- is a diode. The (input/output) is EITHER the input or output line to be protected. This will prevent the input/output lines from going above the +5VDC line and thus protect the IC`s from the 24VDC solenoid bus or the 6. 3VAC light bus power. The earlier run of Gottlieb driver boards did not isolate the MPU board from the solenoid driver transistors, and if a coil shorted out, this can cause serious damage to the MPU board. Essentially making it very expensive to service! Please check the picture on the lower left (here is a circuit diagram with the diodes) and see if you have these on your board. The early boards can be updated by inserting diodes directly at the base of the driver transistors (picture #2), or traces were cut on the back and the diodes soldered in (picture #3). The recommended diodes would be 1N4002 to 1N4005 series, Do not use a 1N4001, at 50V it is not rated with a high enough breakdown voltage. We recommend that ALL Gottlieb System 1 game owners confirm this modification has been...
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.....
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