Hello guys:
I have:
1) 20watt solar panel, maximum voltage: 17.4V, maximum current: 1.15A
2)step down voltage regulator: input 13~40V, 12V constant output(i used a DC power supply to verify that this module always give me stable 12.27V output when input voltage vary from 13~40V)
3)12V 0.95A water pump.
I connect the solar panel to a voltage regulator and to power the water pump.
Before i make a close loop by connecting my load, water pump, with the regulator, i test the input pin of the regulator, it's something like 20.45V. Question 1, why do i get more voltage than what the spec sheet said about the maximum voltage? i am supposed to get 17.4V, according to the spec sheet, but i now get 20.45V.
After i connected the load, the input voltage on the input side of the regulator drop from 20.45V to 5V, and the current flow to the water pump is 0.8A, (which is measured by a ammeter connect the water pump in series), that makes up a total of 4W power.
Question 2, This is a 20watt solar panel, i am supposed to get around 20watt, now, i only have 4Watt power. do you guys know why the energy is missing?
Thank you in advance for your help.
Jian
I have:
1) 20watt solar panel, maximum voltage: 17.4V, maximum current: 1.15A
2)step down voltage regulator: input 13~40V, 12V constant output(i used a DC power supply to verify that this module always give me stable 12.27V output when input voltage vary from 13~40V)
3)12V 0.95A water pump.
I connect the solar panel to a voltage regulator and to power the water pump.
Before i make a close loop by connecting my load, water pump, with the regulator, i test the input pin of the regulator, it's something like 20.45V. Question 1, why do i get more voltage than what the spec sheet said about the maximum voltage? i am supposed to get 17.4V, according to the spec sheet, but i now get 20.45V.
After i connected the load, the input voltage on the input side of the regulator drop from 20.45V to 5V, and the current flow to the water pump is 0.8A, (which is measured by a ammeter connect the water pump in series), that makes up a total of 4W power.
Question 2, This is a 20watt solar panel, i am supposed to get around 20watt, now, i only have 4Watt power. do you guys know why the energy is missing?
Thank you in advance for your help.
Jian