Circuit Element Recommendations

[kjnhu]

Could someone please recommend part values for the following components, or tell me if they do not exist:
1. differential op-amp that can source enough current to turn on a BJT and an LED, and also outputs a voltage near the +-5V inputs
2. a BJT that can withstand up to 2V across it
3. An LED with a breakdown voltage of greater than 5V
4. An PNP Transistor that can withstand very large voltages but turns on with below 5V difference.
5. The connectors that you see on a voltmeter to plug the testing leads into.
Thank you for any help you can be.
Kevin

 

[ranger]

Consider Looking through some datasheets to find the specs you want.

http://www.onsemi.com/PowerSolutions/taxonomy.do?id=797
http://www.onsemi.com/PowerSolutions/taxonomy.do?id=453
http://www.roithner-laser.com/LED_diverse.htm
http://www.theledlight.com/led-specs.html

 

[piercas]

1. For the differential op-amp, a good recommendation would be the LM324, which has a high output current of up to 20mA and a wide supply voltage range of +-5V. It also has a rail-to-rail output, meaning it can output voltages very close to the supply voltage.

2. A suitable BJT for this application would be the 2N3904, which has a maximum collector-emitter voltage of 40V and a minimum current gain of 100. This would allow it to withstand up to 2V across it and still provide enough current to turn on the LED.

3. A recommended LED for this would be the 5mm red LED with a breakdown voltage of 5.5V. This would ensure that it can withstand the 5V input and still have a safety margin.

4. The PNP transistor that meets these requirements is the TIP120, which has a maximum collector-emitter voltage of 60V and a low turn-on voltage of 3V. This would allow it to withstand high voltages while still being triggered by a low voltage difference.

5. For the connectors on a voltmeter, you can use standard banana plugs or alligator clips. These are widely available and would be suitable for testing leads. Make sure to choose ones that are compatible with your voltmeter.