Recent content by wasabilumen

Thanks a lot! I will let you know how is the circuit behave.

Hello, yungman, May be it is somethingwrong with the simulation program.Book the elements need sometime, but I will try to build the circuit and also try to use a current-chip, to see which one performs better. Any suggestion which mosfet to use? Regards, Jining

Thanks a lot. I have searched for "constant current source IC", seems like I searched the wrong word. Ref200 seems really good for me.

Thanks for your advise,Enthalpy, any suggestion for a constant current ship? I have checked some chips, but all of them is not precise enough for my applycation.

Hello， yungman， Thanks for you detailed explanation. I will follow your suggestions, try to build the circuit. Having a good weekend! Regards, Jining

Hello, yungman, really really thanks for you replying. 1. I changed zener diode to a voltage reference. 2. For the BJT work as constant current source means BJT work in active region, Ic value was controlled by Ib, right? In simulation,I use a BJT 2n2219, change +v to 10v, and adjust the...

Here is the datasheet

hello, yungman, thanks for answer. 1. datasheet of zener diode is attached. 2.yes,by not accurate. I mean the current read by the meter change as I change the R1. 3.Then should I change a zener diode or change a R1? I calculate the R1, IDiode = (Usource - Uzd) / R1 a.R must be small...

Hello, everyone, I have to design a constant current source for NTC, to have a more precise measurement. The NTC resistance used range is 1kΩ~13kΩ. I have tried several circuits, but the problem is the the current is not precise enough even in simulation. 1uA difference All the...