Survey - SEQ-9700 relay outputs

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VK4GHZ
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Survey - SEQ-9700 relay outputs

Post by VK4GHZ » Sun Nov 03, 2019 1:21 pm

Hi all

The SEQ-9700 sequencer provides the following nine relay outputs:
* 144M PA
* 144M LNA (I use the term LNA, but interchangable with mast head preamp, etc)
* 144M Antenna Switch
* 430M PA
* 430M LNA
* 430M Ant Sw
* 1200M PA
* 1200M LNA
* 1200M Ant Sw

All of the these relay outputs are independently configurable via the GUI with lower and upper frequency limits.

They can be switched to +13.8V (this is derived from the IC-9700, and a 800mA shared limit applies) -or- GND.

This is configured via internal jumpers.

In most cases I expect switching to GND, especially for Power Amplifiers, will be the most convenient.
SEQ-9700-Rev4_3.jpg
Survey Question:

There is the opportunity to add another jumperable option to a common bus.
'CBus' would use a spare pin on the DB15 interface where you could feed an external +28V supply into the box and be switched out.

This might be handy for directly switching the hot side of 28V relays , rather than GND.

Q) Do you require the ability to switch an external supplied voltage out, or is +13V and GND sufficient?



* There is also a 10th relay output for transverter mode operation.
This is an isolated N.O. relay output (ie both pins appear on the DB15) so you can switch what and how ever you like.
Adam, Brisbane
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Re: Survey - SEQ-9700 relay outputs

Post by VK1JA » Sun Nov 03, 2019 3:33 pm

Hi Adam,

Having the ability to switch an externally supplied voltage would be very beneficial.

Thanks

Jayson

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Re: Survey - SEQ-9700 relay outputs

Post by VK3QI » Sun Nov 03, 2019 4:23 pm

That is an excellent idea Adam.

With the availability of (relatively cheap) 28 volt relays on the second hand market that would be great.

What would be the current limit on the in and out lines (?) - presumably limited by the size of the board tracks to the DB15?

Cheers

Peter VK3QI

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Re: Survey - SEQ-9700 relay outputs

Post by G1LPS » Mon Nov 04, 2019 12:48 am

the ability to switch 28v would be a great addition.
thanks
Terry G1LPS

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Re: Survey - SEQ-9700 relay outputs

Post by VK4GHZ » Mon Nov 04, 2019 12:32 pm

VK3QI wrote:
Sun Nov 03, 2019 4:23 pm
What would be the current limit on the in and out lines (?) - presumably limited by the size of the board tracks to the DB15?
Hi Peter

Yes, the current limit would be determined by the PCB trace width and length.
The underside of the PCB is rather 'busy' with many components and traces, and this trace is currently 0.3mm wide.
A calculator suggests, for the 1oz copper, there would be a current limit of 1.0 amp over it's length for a 10 degree rise in temperature.

The 28V SMA relays I have draw about 80mA.
Considering there could only ever be 6 relays activated at anyone time (3x LNA and 3x Ant Sw relays), this trace should do. 6 x 80mA = 480mA.

If the end user should accidentally short this supply rail to GND, then you also have built in fuse protection! ;-)


I originally considered having an internal 12V to 28V DC-DC inverter for the 28V rail, but the ~480mA of relay current equated to a 13.8V ~1.5A draw. This alone exceeds the 1A limit Icom specifies the on the IC-9700's ACC port, which is why it has to be an externally supplied voltage.
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Re: Survey - SEQ-9700 relay outputs

Post by VK3QI » Mon Nov 04, 2019 5:57 pm

Thanks Adam,

I like the idea of the "fuse".

Cheers

Peter VK3QI

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Re: Survey - SEQ-9700 relay outputs

Post by OZ2M » Tue Nov 05, 2019 8:16 am

Hi

Here are some more input.

To switch external relays, and other power stuff, you could take a look at the ULN2803A, or one of its siblings, and put it in a socket, like done on the RFzero board: http://www.rfzero.net , so it can be replaced easily in case it is fried. The ULN2803A can switch eight ports at 50 V and 500 mA each. Then you can probably also avoid the use of relays.

I can't see what MCU you plan to use. But the Atmega328 could be an idea because then it can be Arduino compatible. Thus upgrading the F/W is easy.

Some 20 years ago I designed this sequencer: http://rudius.net/oz2m/seqmulti.htm than can both sink and source and the polarity is configured.

Does the sequencer control the radio PTT or is it the other way round?
Is there an input for hand-PTT, foot-PTT and PC-PTT? The latter may control the sequence in a different way compared to the hand/foot-PTT, e.g. programs that have built-in timing.

Do you have decoupling capacitors and RFI chokes? If not clock frequency and MCU cycles could be an issue.

Bo

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Re: Survey - SEQ-9700 relay outputs

Post by VK4GHZ » Thu Nov 07, 2019 2:14 pm

I'm not sure what I was thinking!
It occurred to me, after moving umpteen parts to the other side of the PCB, the solder paste stencil that has been made to suit the current revision PCB would be rendered useless.

So, I have removed the PCB trace from the 13.8V supply (sourced from the IC-9700) to one side of the relay output jumpers.

This means the nine output relays can be individually jumpered to switch to GND, or to an external supply.

I think it's best if the IC-9700 (via it's ACC connector) is not used as a voltage source beyond powering the controller board itself, because if that rail were to be shorted to GND then that could create a problem within the IC-9700, which should be avoided.

If you have a mixture of relay voltages, then you can switch the hot side of some relays to the external voltage, and switch other relays on the GND side.

Given the limited amount of participation in these surveys (which becomes a defacto gauge of interest), I am going to freeze the hardware design at this point. I can no longer justify spending any more time on this with such limited interest.

Thanks to all who have offered input. :thumbup:
Adam, Brisbane
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Re: Survey - SEQ-9700 relay outputs

Post by VK1JA » Thu Nov 07, 2019 2:51 pm

G'day Adam,

Great idea about the jumpers, keeps it simple yet very flexible.

Don't take the participation of the survey as an indication of the interest in the SEQ-9700, I honestly think they will sell like hotcakes once 9700 owners realise you've filled a big gap.
Last edited by VK1JA on Thu Nov 07, 2019 7:52 pm, edited 1 time in total.

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Re: Survey - SEQ-9700 relay outputs

Post by OZ2M » Thu Nov 07, 2019 7:08 pm

Don't despair. Often in product planning the potential users cannot envisage the possible use. The saying goes that if Henry Ford had asked what the potential customers wanted they would have said faster horses.

If the F/W is easy to change, e.g. Arduino based, then the sequencer can most likely be used for the IC-7300 too. Either as HF + 6 m + transverter or HF + 6 m + 4 m. So perhaps the name should be SEQ-7397 :clap: The volume of IC-7300 is much higher than the IC-9700 thus less risk.

With easy to change F/W the user may even tailor the functionality even more, e.g. two control on HF, three on 6 m and four for transverter use …

Bo

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Re: Survey - SEQ-9700 relay outputs

Post by VK4GHZ » Thu Nov 07, 2019 7:44 pm

Hi Bo

This sequencer has been specifically tailored to suit the IC-9700.
The 9700 is a unique class of Icom radio with the quirks of the 'Main' and 'Sub' bands and Sat Mode, etc.

As I don't own an IC-7300 (or an IC-9100 for that matter) I wouldn't be able to customise the firmware to suit accordingly.

Unless someone wants to donate either one of these to me! ;-)

I believe there are basic plain vanilla general purpose CI-V decoders already out there that would better suit a conventional HF/6 box like the 7300, so I designed the SEQ-9700 to be a purpose built "next level" device that had lots of features beyond a basic 2/70/23 PA relay driver. Features you may not use initially, but could grow into.

Appreciate your input though. :thumbup:

Yes, both the main MCU and touchscreen firmwares will be upgradable by the end user if/when updates are required.
Adam, Brisbane
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Re: Survey - SEQ-9700 relay outputs

Post by VK3VG » Mon Nov 11, 2019 3:31 pm

Hi Adam
I believe you are on the right track and keep going on your design.
Put me down for 1
Thanks
Trevor
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