I'm am about to print out a PCB in order to build a metal detector , here is the design. http://www.geotech1.com/pages/metdet/projects/twinloop/twinloop.pdf
I am missing a transistor, a TIP31A.
Have looked in a alternative transistor catalogue and have found no results for this component, So I am wondering if anybody on the forum knows of any possible alternatives that will just about to the job ?
Need to hand the detector in in two days so any advice will be very helpful !
Thanks guys.

 

If you can't buy, what numbers do you have or get ?

 

I have 32C, 34, 41, 120, 121, 126, 127, 3055. And many other transistors available as i'm in college so name any you believe will work !

 

Rapid Electronics have them

http://www.rapidonline.com/FFSearchResults.aspx?query=tip31&filterSearchScope=1

 

I do not have time to order unfortunately ! if you could name any you belive will work I will check if they are in the store room

 

I do not have time to order unfortunately ! if you could name any you belive will work I will check if they are in the store room

Why don't you read the datasheets yourself and see if you have an equivalent. Things to consider with comparison would be:

• NPN or PNP?
• hFE / Beta
• Darlington / super transistor?
  
• Bandwidth (MHz)
• Voltage & current ratings

 

TIP41

 

Tip41

 

TIP41 - yes. 5A instead of 3A, simple substitution.

TIP121 - no. This is a darlington transistor, and might not behave the same as the TIP31 because of the different effective base-emitter voltage.

ak

 

Not having time to order is not a good reason as Digi-Key ships same day and had stock $0.50 each but the TIP41 is the higher power version as long the case lead hole size is compatible with A or AB case and 60 mil hole..

http://www.digikey.com/product-detail/en/TIP31A/TIP31A-ND/1052570