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Recent content by E2005

  1. E2005

    scaling and offsetting analog output

    VE1BLL and ScottyUK 'm' and 'b' are depedent on maximum supply voltage. My supply is chosen by user it can be between 5-20V. The only thing that does not change is the sensor output which is 0.5V to 4.5V. That needs to be mapped to 0.5V=25% of suppy and 4.5V=75% of supply. If supply was fixed...
  2. E2005

    scaling and offsetting analog output

    ScottyUK , When i map 0.5 to 4.5V input range to current required output range which is 0-8V i get a transfer function Vo=sVin + b where Vo= desired output, Vin is the sensor signal (0.5 to 4.5V) and s and b are the span and offset. For s= 2 and b=-1. I get the desired output. If there was an...
  3. E2005

    scaling and offsetting analog output

    I cannot use an Arduino Uno, just looking for an analog way to scale the sensor signal which varies from 0.5V to 4.5V to 25% of supply to 75% of supply respectively. The supply can be chosen between 5V to 20V DC
  4. E2005

    scaling and offsetting analog output

    This is NOT onesie.
  5. E2005

    scaling and offsetting analog output

    Mike Yes, sorry misunderstood your question. The supply can vary from 5V to 20V DC. The sensor output will always be between 0.5V to 4.5V but the supply can vary from 5V to 20V.
  6. E2005

    scaling and offsetting analog output

    The supply is +8V. I can scale output to this particular supply voltage with opam but the problem is user wants to be independent of the supply voltage. They want to choose a desired supply voltage and the out put sinal (0.5v to 4.5V) needs to scale to it in the following way - 25% of...
  7. E2005

    scaling and offsetting analog output

    I have a 2.5V DC output signal ( its range is 0.5V to 4.5V), it needs to be scaled from 25% of supply to 75% of supply voltage. The supply voltage is a variable.Due to constraints i cannot use microprocessors or other fancy signal processing parts, need to stick with basic parts like opamps ...
  8. E2005

    IEC for mechanical devices/products

    I am looking for a satisfatory answer to the question of which IEC standards apply to mechanical devices/systems in general ?? does IEC 60601-1 3rd edition apply to mechanical parts/devices? IEC standards seem most applcable to devices which have any kind of electrical element but say you have...
  9. E2005

    IEC standards application to mechanical systems

    I am looking for a satisfatory answer to the question of which IEC standards apply to mechanical devices/systems in general ?? does IEC 60601-1 3rd edition apply to mechanical parts/devices? IEC standards seem most applcable to devices which have any kind of electrical element but say you have...
  10. E2005

    compliance for medical device

    I am new to compliance. We make two types of devices, one uses a stepper motor with chopper drive and operates on a 16V, 1500mA rechargeable battery. Its insulated from body. There is not wirelss. The other one is similar to a massage vibrator with wireless control, the vibratory is insulated...
  11. E2005

    Question on analog sensor signal processing

    Apologies in my example. 1 kg should produce 5V output, but you get any where from 4.5 to 5.5. This is just for example, in my case its not a 1V variation, it varies. Also if I run a test when the sensor is new, make a loop up chart for future and later if the sensor starts drifting (offseting...
  12. E2005

    Question on analog sensor signal processing

    Thanks to all your inputs. Its an pleasure to be here. Firstly I was talking about the drift over time in the sensor not the circuit.Kalman filtering does seem like the best solution but hoping for an easier solution.By repetability I meant for the same input you dont get the exact output. Such...
  13. E2005

    Question on analog sensor signal processing

    Not sure if its a basic question to ask. If you have an analog sensor and the output drifts over time or output is non repeatable(input being constant). Also assume thats the best sensor you can get and you are relying on those values to set thresholds etc. Is there a way to take care of...
  14. E2005

    Power supply rejection ratio LM386

    Hi, I had read that power supply rejection ratio(PSRR or PSR) follows open-loop gain curve(or CMRR curve) meaning it drops off with frequency. I saw that in many opam datasheets like OP1177 etc but when looking at LM386 data sheet(page 4, PSR Vs frequency curve) it shows reverse trend , meaning...
  15. E2005

    Transient suppressor

    can anyone tell the basic difference between using an off the shelf transient suppressor chip ( such as Texas Instruments SN75240) and making ones own RC filter circuit.Apart from performance differences(cut off etc) are there other differences and which is better.

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