I want to make an electrical circuit with pulse voltage generator. In pulse voltage generator specification there is a voltage parameters, such as: 0-20 V (into 50 ohm).
what is the meaning of into 50 ohm?
then, how to measure the current as a pulsed? can we use oscilloscope to measure current?
what is the meaning of into 50 ohm?
then, how to measure the current as a pulsed? can we use oscilloscope to measure current?
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Spec means the generator can generate voltages varying between zero and 20 volts into a 50 ohm load. That implies that the generator output has a 50 ohm source impedance, and that you should use 50 ohm coax cable for connections. How important this is depends on the specs of the generator, for example, rise and fall times.
With degraded performance, you can use a higher impedance load to get more voltage, or a lower impedance load to get less voltage, but you would have to read the specs carefully to see if that could harm the generator. But, as I said, the performance would be degraded if you don't maintain the specified 50 ohms throughout.
Using a scope to measure current is possible. But first, see if you can use ohm's law. For example, 20 volts into 50 ohms, means the current is 20/50 = 0.4 amp.
If not, you need a small value resistor inserted in series, such as 1 ohm. Then use two matched scope probes, one on each side of the resistor, and set the scope to differential input mode, which subtracts the two inputs. This will give you the voltage across the resistor, and from that you can calculate current.
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With degraded performance, you can use a higher impedance load to get more voltage, or a lower impedance load to get less voltage, but you would have to read the specs carefully to see if that could harm the generator. But, as I said, the performance would be degraded if you don't maintain the specified 50 ohms throughout.
Using a scope to measure current is possible. But first, see if you can use ohm's law. For example, 20 volts into 50 ohms, means the current is 20/50 = 0.4 amp.
If not, you need a small value resistor inserted in series, such as 1 ohm. Then use two matched scope probes, one on each side of the resistor, and set the scope to differential input mode, which subtracts the two inputs. This will give you the voltage across the resistor, and from that you can calculate current.
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That means that the pulse generator can produce 0 to 20V if connected to a 50 ohm load. If you connect it to a smaller resistance, it may not be able to produce as high a voltage. (The lower the resistance, the more energy is required to produce a given voltage across it.)
P = V^2 / R
So to produce 20V into a 50 ohm load requires 8 watts (20*20/50=8). This is something the pulse generator can do. To produce 20V into a 10 ohm load requires 40 watts (20*20/10=40). This the pulse generator cannot do.
P = V^2 / R
So to produce 20V into a 50 ohm load requires 8 watts (20*20/50=8). This is something the pulse generator can do. To produce 20V into a 10 ohm load requires 40 watts (20*20/10=40). This the pulse generator cannot do.