Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

car alarm

Status
Not open for further replies.
I looked at https://www.electro-tech-online.com/threads/the-oscilloscope.56/. ElectroMaster, if you read this, you might want to comment, since I'm critiqueing your circuit.
I believe the base resistors are way too large. The LED is going to draw around 7ma. The buzzers that I could find specs on draw at least 5 or 6 ma. That's 12 ma collector current. The base current is about 38 ua. For the transistor to saturate, you will need beta to be over 300. This is not common in a garden-variety transistor, certainly not at low Vce, which is where the operating point is. I would make the base resistors no larger than 22k. 10k would be safer.
 
Status
Not open for further replies.

Latest threads

New Articles From Microcontroller Tips

Back
Top