Hi to all...
I'm having troubles while triyng to find a way to convert a signal to another...
Explaination:
I have 2 devices with 2 different acquisition systems (both automotive ecu). I need to let both share a NTC temperature sensor.
The first acquisition system use a strange (but nice) way to condition the signal...
It uses 2 bias resistors, and switch them at a certain temperature for gain accuracy, giving us a signal like this:
This is a warmup sample.
I need to not touch or modify this system...
I've computed that the first bias resistor (low temperature) is 3,9k, and the second is 350ohm.
The second system want a linear response from the NTC, and use a normal partition resistor conditioning scheme. A bias resistor to +5, the other lead of the bias to acquisition and with a terminal of the NTC, and the other lead of the NTC is at ground.
On the second system i can disable the bias resistor, and let it to acquire the pure signal conditioned by the first system, but the signal is not suitable...
This evening i try to find a point on the original system where i have a
0-5v signal, for know when there is the bias resistor swap...I'm sure that it's possible to done it using only analogic devices, without using uController, ADC and DAC...
Anyone has an advice on how to slove this problem?
Thanks for any help...