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Does voltage drop increase with load?
When you draw more loads you are lowering the load impedance. This increases the voltage drop across the source impedance. For example if the load impedance were the same as the source impedance the bus voltage would drop to 50% of the open circuit voltage.
Why does load cause voltage drop?
Wires carrying current always have inherent resistance, or impedance, to current flow. Voltage drop is defined as the amount of voltage loss that occurs through all or part of a circuit due to impedance. This condition causes the load to work harder with less voltage pushing the current.
What is off load voltage?
A circuit and corresponding method for reducing standby power and improving no-load to full-load regulation for ringing choke converters by maintaining a reduced duty cycle, with longer off time at no-load, while maintaining the output voltage swing closer to the full-load level.
Why does the output voltage drop when driving optocoupler?
The schematic is done as the pic is connected to a resistor (then to the anode of the led), and the cathode of the led is on the ground. I need to bring at least 10mA to drive the optocoupler, but the more I reduce the value of the resistor (between the pic and the anode), the more the output voltage drops.
Do you need a high current for optocoupler?
Yes, better stated that way. The other thing you need to look at is the current transfer ratio of the optocoupler. Depending on the device you are using this can be very small, sometimes as low as 10%. This means that 10mA gets you 1mA out. Normally optos do not require such a high current.
How to calculate optocoupler efficiency in a circuit?
The most convenient way of specifying optocoupling efficiency is to quote the output-to-input current transfer ratio (CTR) of the device, i.e., the ratio of the output collector current (I C) of the phototransistor, to the forward current (I F) of the LED. Thus, CTR = I C /I F.
How is the optocoupler connected to the TTL?
Here, the optocoupler LED and current-limiting resistor R1 are connected between the 5V positive supply rail and the output-driving terminal of the TTL device (rather than between the TTL output and ground), because TTL outputs can usually sink a fairly high current (typically 16mA) but can source only a very low current (typically 400µA).