Re: Nextion Display vs 1602 LCD - Current Consumption #ubitx

Ian Lee
 

Michael

Perfect !!!
I considered using a $ 2 price regulator for RPI on ebay, but decided to cancel.
I will disassemble another transceiver to find the heat sink

Ian


2018-06-25 10:37 GMT+09:00 Michael Babineau <mbabineau.ve3wmb@...>:

Today I upgraded my uBITX (v3) to use KD8CEC v1.094 and a Nextion 2.8" display, so I am now able to answer my
previous question about current draw of the display and whether the L7805 regulator on the Raduino board is up to the task
of powering this display. 

Prior to doing the upgrade I measured my RX current draw as 162.5 mA, running off of a 12.5 v SLA battery. 
A previous posting to this group established that the 16x2 LCD Display draws about 21 mA so the rig + Raduino (without LCD) should
be around 142 mA

With my Nextion 2.8" Display and backlight set to 100 % I am now seeing a total current draw for the uBITX of  250 mA.

That indicates that my 2.8" Nextion Display is drawing about 108 mA.   

The L7805 regulator on the Raduino board is rated for at least 1A so it should be fine with a 250 mA total current draw.

I did go ahead and put a heatsink on it and I even used some silicon-based heatsink compound. 

For fun I took a meat thermometer and held it against the Heatsink and I got a reading of 56.5 C !
The rig had been powered up for over an hour.  This part is rated for up to 150 C. 

My recommendation is that if you are going to add the Nextion Display you should  put a TO-220 compatible heatsink on the L7805 5V regulator on the Raduino board.

Cheers

Michael VE3WMB 




--
Best 73
KD8CEC / Ph.D ian lee
kd8cec@...
www.hamskey.com (my blog)

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