Op-amp or how to make a voltage or signal stronger.

Discussion in 'General Electronics Chat' started by Whatashame, Dec 15, 2015.

  1. Whatashame

    Thread Starter Member

    Nov 30, 2015
    I need to make the output of a light or sound shield stronger to operate a 3 - to -5 volt relay. The shield is small and requires 3 to 5 volts. Really supposed to use 5 volts. I'm hoping 3 volts will do. This project is my robot car I posted about before. The output of this 3 wired shield will not operate the relay. Someone has already told me that I will have to amplify the output. For starters, I don't know if the output is a voltage or a digital signal. I believe it's a voltage. Does an Op-Amp transistor do the trick? And if so, could you show me how. Once I learn this stuff I will never have to ask again. Be Kind and help. Thanks! OK more information about the shield. It can be used with Arduino but is generic brand. It measures, 13.83mm x 32mm.Has a #103 trimmer, 1tiny red power Led, a green Led which lites when sound is (1) detected. A LM393 IC Chip, I believe the chip is a dual Op-Amp or dual voltage chip. The terminals from left to right, DO, GND, Vcc. Senser is on top, neg. on left, pos on right. I replaced the senser with small female jacks. This way I can use any senser I want without soldering the shield. I take it, that shield is just another way of saying electronic PCB board. The shield has 2 "caps" #102 ,(real tiny), before IC and trimmer resistor. After trimmer and IC is 2 # 103/ no letter C next to them. And 2 tiny other electronic rectangular parts unknown to me. All tinny, tiny parts are rectangular in shape. My power source is 3 volts.
    Last edited: Dec 15, 2015
  2. GopherT

    AAC Fanatic!

    Nov 23, 2012
    The forum helps those who help themselves. You will have to help yourself by describing what your shield does or, if you have no idea, at least give us a part number/model number to look up. Then you will have to give us part number of relay(s) and describe your power supply. Because you use the word "shield" I assume this is an arduino project. Please clarify.
    Whatashame likes this.
  3. Papabravo


    Feb 24, 2006
    Whatashame likes this.
  4. hp1729

    Well-Known Member

    Nov 23, 2015
    Yes, I take "shield" to be Arduino for "Interface board". I don't think he is describing a motor shield. LM393 (dual voltage comparator) won't do it.
  5. wayneh


    Sep 9, 2010
    You should be able to use a single transistor (or a darlington, which contains 2). To be more specific requires more information. The current draw of the relay and the nature of the output signal (voltage when hi or low, current capability) would help. You need to know if you want the relay to trigger when the output voltage goes high or goes low.

    I'm just reiterating what PB said.