| Electronics > Projects, Designs, and Technical Stuff |
| Another counstant current load for critics |
| << < (3/3) |
| SiliconWizard:
This project is a pretty basic voltage-to-current converter. There's nothing fundamentally "wrong" with it. As is, it has some limitations, but it can work fine for a range of conditions. (I hate schematics with basic elements like opamps not drawn as actual opamps...) As it is, one of the opamps is used as a voltage buffer for the "reference" voltage coming from the pots; then the buffered voltage is divided by 2 (to limit the current range). Let's call it Vref = Vpot/2. With R6, the resulting current range would be 0 (there will be an offset though!) to 4.5A: Iload = Vref / R6. With the LM358 and an IRF540, the probability of it oscillating is small IMO, but not zero. You can add a capacitor in the feedback loop to avoid oscillations. Due to the topology, the working voltage range is also limited. R6 basically drops the voltage reference (= R6*Iload). Obviously the input voltage must be greater than Vref + Vds. This basic topology has been discussed many times on here, so you should be able to find a number of threads dealing with it and the possible traps (including oscillation). As to whether the MOSFET mostly works in the linear or saturation region, I'll leave it as an exercise. :popcorn: |
| 001:
Thanx a lot Can U link me with better project at these level? |
| SiliconWizard:
You can take a look at this thread: https://www.eevblog.com/forum/projects/mosfet-and-opamp-load-tester-constant-current-load |
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