Re: Nextion with KA78T05

Murray Wills (ZL2IQ)

Hi I did the same only the KA78T05 I got (bought 10 cause they were cheap) went red hot 🥵 so I shut it all down and went back to the step down to power the Nextion. Luckily it didn’t seem to introduce any noise for me.

Something wrong with the KA78T05’s as they should have been able to handle the current.

From: <> on behalf of MVS Sarma via Groups.Io <mvssarma@...>
Sent: Tuesday, September 17, 2019 4:12:57 AM
To: <>
Subject: Re: [BITX20] Nextion with KA78T05
I suffered with 10pcs of  bad 78t05 from ali seller and demanded refund and got it.

On Mon, 16 Sep 2019, 9:37 pm Herman Scheper, <Hsrscheper@...> wrote:
I am using the Nextion 5"display. When building my Ubitx V5 I used a small step down converter to generate the 5V for the Nextion display. It all worked 100%
Now the building is almost finished i want to replace the 5V stepdown converter. ( It is giving a little amountt of noise…)

I ordered ( Aliex..) 5 pcs of KA78T05 TO-220 stabilisors. ( is the 3A version-  )

Then I replaced the 7805 mounted on the Arduine and replaced it for the KA78T05 version…. No working Arduino and no working display.

I find input=12V output=0V.   Checked before and after the pinning  1=input / 2 = earth/ 3 =output   Find a datasheet on Internet and can not find what I am doiing wrong.

After that make a test print only for the KA78T05 and I can not get the 5V output. Output also on a 2nd KA78T05 is still 0Volt.   Frustrating.  ( I used a 7809 on the same test and output was 9.00 Volt!)

What I am doiing wrong...…….?     ( ordered today local few 78S05   ( = 1.5A version  )

So who knows what I am doiing wrong...?                       Tnx.  Herman

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