[TriEmbed] Anyone need some darlington transistors ?

[Scott Hall]

P.S.  $0.25 a piece  (my cost)

On Fri, Sep 16, 2016 at 4:11 PM, Scott Hall <scottghall1 at gmail.com> wrote:

> I'm buying a bunch of TIP120 darlington-pair transistors for driving
> larger loads from microcontroller I/O pins.
> https://www.arrow.com/en/products/tip120/stmicroelectronics?wm_g_
> phyloc=1023285&wm_g_intloc=&gclid=CP_hkIbJlM8CFQooaQod7A0E4g&utm_
> source=google&utm_medium=cpc&utm_term=tip120&utm_campaign=
> us+-+sku+-+stmicroelectronics+-+dynamic+inventory#partsDetailsDatasheet
>
> Rated for up to 60V up to 5A.  In my case 12VDC @ 1.5A
>
> Anybody want some?
>
> For those who aren't familiar with them, a pair of matched transistors in
> a Darlington configuration:
> [image: Image result]
>
> can switch larger loads than just a single transistor.  Here is a typical
> circuit:
>
>
> By using 5 Volt power supply and DC Motor with 12 Volt and 1 A maximum
> operating current:
>
> RC = 0 Ohm (not use, connect directly to the 12 Volt power)
> IB = IC / hFE = 1 A / 1000 = 0.001 A
> RB = (VPORT – VBE) / IB = (4.2 – 1.4) / 0.001 = 2800 Ohm, use *2K7 Ohm*
> resistor
> P = (VPORT – VBE) x IB = (4.2 – 1.4) x 0.001 = 0.0028 watt, use *0.25
> Watt* resistor
>
>
> --
> Scott G. Hall
> Raleigh, NC, USA
> scottghall1 at gmail.com
>



-- 
Scott G. Hall
Raleigh, NC, USA
scottghall1 at gmail.com
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