Regarding the Bentley power supply issue for the unit
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Why does the Bentley 3300 preamplifier require -24V instead of 24V for power supply? Also, as shown in the formula in the figure, why is it added on the remote end? Should I cut back soon? Please give me some advice, seniors
Regarding the power supply issue for the Bentley unit: 1. The reason why the power supply for the Bentley 3300 preamplifier is -24V instead of 24V is that this -24V refers to a negative voltage with respect to ground, and it is used to control negative terminals of components such as NPN transistors in the circuit. If 24V positive is used, the control components will not function. 2. Regarding the issue of adding at the far end and subtracting at the near end in the formula, this is due to the presence of cable resistance. The longer the cable, the greater the resistance, resulting in a voltage drop. To ensure the proper operation of remote devices, it is necessary to apply a certain voltage compensation at the remote end ； At the proximal end, the cable length is shorter and the resistance is lower, so no additional voltage compensation is required. -