[minima] Re: band switching
- From: "Steve VK2SJA" <vk2sja@xxxxxxxxxxx>
- To: minima@xxxxxxxxxxxxx
- Date: Sun, 9 Feb 2014 18:34:07 +1100
Hi All,
Seems to my mind that a lot of potential exists for the "software" to
think your on one particular band while the 4017 is on another. But even
if I'm mistaken and this arrangement turns out to be bullet proof what
advantage does it have over the 3 bit BCD to one of eight lines selected
that Mark is preposing?
Both appear to use the same number of IO lines. Unless I've misunderstood
something.
So the advantage is?
> sudarmanta,
>
> you won't know which band you were on. so, each time you want to
> transmit,
> reset and then pulse it enough number of times so you are on the correct
> band.
>
> - f
>
>
> On Sun, Feb 9, 2014 at 12:06 PM, Sandeep Lohia
> <sandeeplohia12@xxxxxxxxx>wrote:
>
>> why burn extra energy in relays??? they always ON !
>>
>> here using something like : (see attachments)
>> it's just mine is MIL-RECYCLED, (air-wound properly angled)
>> hope pictures say complete story :D
>>
>>
>>
>> On 09/02/2014, Ashhar Farhan <farhanbox@xxxxxxxxx> wrote:
>> > here's another idea:
>> >
>> > use a CD4017. the 4017 has upto ten outputs. only one goes high at a
>> time.
>> > as you pulse the clock input, the high moves to the next pin.
>> > so, what you do is this :
>> > 1. Use one pin to reset the CD4017 (the high moves to the pin'0').
>> > 2. generate low to high pulses to move the high output to the desired
>> band.
>> >
>> > as the CD4017 outputs a high, you can use this to drive a 2N7000 to
>> switch
>> > the relays. the 2N7000 has built-in diode to prevent the flyback
>> surge.
>> >
>> > - f
>> >
>>
>>
>> --
>> --
>> Please encourage recycling, reuse or repairing of E-waste.
>> â7â3â âdâeâ âVâUâ3âSâXâTâ
>>
>
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