Re: Best pc design for SDR

Augusto <hb9tza@...>

Yes, I was just thinking to some diodes in series ...
I do so also for the led lighting, I've seen that at 13.8V some does not last, so with led stripes I keep 4 diodes in series and this is vy OK, good light but no heath .
Some car, not too new, may get to 16-17 Volt peak , and it should also be fine to put a coil and a large C to avoid hi-spikes.
With new cars, where electronics aboard is more, the voltage regulators are better, too.
Getting also  a model battery pack
instead of the car battery may be even cheaper than the PC own battery pack, in some case.
Using the FT-817 a single battery pack could supply both laptop and transceiver, too. But mostly when in /P I use the FT-857 or IC-7000, a bit more current hungry .
I have only to test it; the old laptop is suitable for this, as I do not worry so much if it does QRT ...
73 and thanks, Siegfried !
                                           Augusto HB9TZA / I2JJR

Il 06/02/2018 18:10, Siegfried Jackstien ha scritto:

if it really runs with only 3 lipos in series then it should run from the car battery fine ... just leave the 19v connector open ... max voltage of the car battery can reach above 13.2 (max voltage of 3 lipo in series) so just to be a bit safer i would install a diode or two in series to the voltage (and maybe a cap and a coil or two so any switching noise from internals can not escape that way!!)

i do not know what the max voltage is that your board can survive ... 13.2v??  for sure! 13.8 ?? guessing yes

14.2-14.4 (max charging voltage of a lead acid battery) hmm that is roughly 10 percent more ... maybe it will work fine maybe you will cook the internal switchers (i would try it)

good luck

dg9bfc sigi

Am 06.02.2018 um 14:52 schrieb Augusto:
HI folks,
I was thinking to another solution: I have an old HP that has a power supply of 19V 3A and a battery of 11, 5 V (Li-Ion) so I was thinlking to eliminate the battery and build a 11,5V analogic supply with the needed Amperage.
My question, if anybody is able to answer: should I keep the other battery terminal
I could build also a resistor net to parse the power at the power supply pins; as there will be no power in the Power Input from AC power supply, I suppose it will not try to charge the battery.
I guess the PC internal switchers, having their correct 11,5 DC voltage, will do their job and the PC could be on duty without the need of switching AC inverter generators or switching power supplies, so reducing the RF noise, and being easy to supply the laptop PC from a car battery.
Or not? What do you mean? Any opinion on this matter welcome. Thanks. 

Il 06/02/2018 11:21, jj.dijkhuizen@... ha scritto:
Well, I learned my lesson.
Acer-Aspire will not run on a 12V battery.
A stabilizer 19.37 V/2 A is a no go also.
The adapter is reated 19V/4.47A !!!!
The power source must be a hard one with very low internal resistance..

Thats it.....



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