michael.hamilton Posted May 20, 2014 Share Posted May 20, 2014 I'm thinking of ordering an R8247 accessory decoder to control some lights and buzzers to indicate various track conditions. If I program the decoder to supply continuous output, what exactly would that output be in terms of voltage, AC/DC and current? I downloaded the brochure but didn't see the relevant specs. Thanks in advance for your help. Link to comment Share on other sites More sharing options...
michael.hamilton Posted May 20, 2014 Author Share Posted May 20, 2014 Forgot to say I realise my Select controllers can't change the CVs on the R8247 but I have another controller that can do this. Link to comment Share on other sites More sharing options...
Fishmanoz Posted May 20, 2014 Share Posted May 20, 2014 Don't know for the 8247 because, as you've found, Hornby don't tell us. A check of other brands tells me it will be in the order of 10 volts though. Link to comment Share on other sites More sharing options...
Rog RJ Posted May 20, 2014 Share Posted May 20, 2014 In this thread https://www.hornby.com/forums/hornby-forums/hornby-digital/427/?page=1#post3954 (15:49 14 July 2011) Hornby Customer Care states "The R8247 Point and Accessory Controller (PAD) can in total sink/source approximately 240mA. This is shared; this could be all ports turned continually on drawing a total of 240mA, or a single port turned on drawing approximately 240mA. In order to control larger currents it is possible to use relays in conjunction with the PAD." I would expect the voltage to be 1.5 - 2 volts less than the rail voltage due to the losses caused by the components in the R8247. Link to comment Share on other sites More sharing options...
Fishmanoz Posted May 20, 2014 Share Posted May 20, 2014 But surely we are talking PWM square wave in and DC out, so calculation a little different to that? Link to comment Share on other sites More sharing options...
poliss Posted May 20, 2014 Share Posted May 20, 2014 So why hasn't anyone tested one with a RRampmeter to find out for def? Link to comment Share on other sites More sharing options...
Fishmanoz Posted May 20, 2014 Share Posted May 20, 2014 Don't have access to do this myself at the moment. So what I did was try a search in the NMRA standards, but didn't get anywhere there. So then I looked at the spec for the DCC Concepts continuous output decoder and the answer is 9.5V out with NMRA track voltage in. Given that the output will be NMRA specified, they should all be this voltage. Link to comment Share on other sites More sharing options...
michael.hamilton Posted May 21, 2014 Author Share Posted May 21, 2014 Thanks for the info. If the R8247s are back in stock soon I'll order one. Then I'll measure the continuous output and post it here in case anyone else would like to know. Link to comment Share on other sites More sharing options...
poliss Posted May 21, 2014 Share Posted May 21, 2014 On another accessory decoder it says the output voltage is 1 volt less than the AC input voltage. The input voltage on that decoder is 16v AC from an independent power supply. Link to comment Share on other sites More sharing options...
Fishmanoz Posted May 21, 2014 Share Posted May 21, 2014 Interesting poliss, and maybe there isn't anything specified by NMRA, or maybe specified broadly. When you think about it, the simplest voltage to produce is going to be what comes out of the bridge rectifier from the supplied volts, less losses through the circuit, which avoids any further voltage conversion or regulation. And that is going to be something like the RMS value of the input volts, not that RMS has the conventional meaning if the input comes from the square wave on the track. Link to comment Share on other sites More sharing options...
michael.hamilton Posted June 28, 2014 Author Share Posted June 28, 2014 I can now report that the continuous output of the R8247 is 13.5 volts DC.My next question is whether I can program it so that the outputs operate at non-consecutive addresses.I would like output 1 to operate at address 61 (so that a warning buzzer sounds when I have point 61 in a particular direction), output 2 to operate at address 69 (so that when the fire effect in my tunnel is on a fire alarm will go off) etc.If the addresses have to be consecutive I'm sure I'll work something out. Link to comment Share on other sites More sharing options...
St1ngr4y Posted June 28, 2014 Share Posted June 28, 2014 Hi Michael,The answer to this question is No. You are limited to sets of four consecutive addresses, the first being a multiple of four +1i.e.1 2 3 45 6 7 89 10 11 12etcRay Link to comment Share on other sites More sharing options...
michael.hamilton Posted June 28, 2014 Author Share Posted June 28, 2014 Thanks Ray.I was hoping that CV513 (decoder address LSB) and CV521 (decoder address MSB) might have given me some joy somehow.Seems like I'll have to get used to a new address for one of my points. Link to comment Share on other sites More sharing options...
michael.hamilton Posted June 28, 2014 Author Share Posted June 28, 2014 Just a minor point. The first address does not have to be multiple of four +1.I gave the decoder an address of 69 and I have the four outputs as 69, 70, 71 and 72. Link to comment Share on other sites More sharing options...
Fishmanoz Posted June 29, 2014 Share Posted June 29, 2014 Another minor point - not currently in Sydney but I think 4 x 17 + 1 still equals 69? Link to comment Share on other sites More sharing options...
michael.hamilton Posted June 29, 2014 Author Share Posted June 29, 2014 Now that's embarrassing. And I definitely won't tell you my occupation. Link to comment Share on other sites More sharing options...
gilbo2 Posted June 29, 2014 Share Posted June 29, 2014 Accountant, must be :-) Link to comment Share on other sites More sharing options...
Graskie Posted June 29, 2014 Share Posted June 29, 2014 Yes, my wealthy son is one. I think they call it, "Cooking the Books!" Link to comment Share on other sites More sharing options...
michael.hamilton Posted June 29, 2014 Author Share Posted June 29, 2014 No - not accountant. More embarrassing than that. Link to comment Share on other sites More sharing options...
Graskie Posted June 29, 2014 Share Posted June 29, 2014 Surely not a maths teacher? Link to comment Share on other sites More sharing options...
Fishmanoz Posted June 30, 2014 Share Posted June 30, 2014 We could ramp it up one and go for maths lecturer? Link to comment Share on other sites More sharing options...
michael.hamilton Posted June 30, 2014 Author Share Posted June 30, 2014 I'm afraid I'll have to admit to being a primary school assistant principal. I certainly hope none of my students read this thread. Link to comment Share on other sites More sharing options...
RDS Posted June 30, 2014 Share Posted June 30, 2014 Best to keep quiet Michael - Oops too late! Link to comment Share on other sites More sharing options...
St1ngr4y Posted June 30, 2014 Share Posted June 30, 2014 Maybe if I'd said "The highest of the four addresses will be a multiple of four" it might have been less confusing? :-)Ray Link to comment Share on other sites More sharing options...
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