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Bes900 LED modification

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  • Bes900 LED modification

    Hi guys,

    My machines out of warranty and I'd really like to put some LED lights to illuminate the brewing process. I managed to get my hands on small 12vdc strips of LEDs and opened my machine to have a look today.

    Ideally, I would love the led to behave the same way as the power switch light. But the power switch and LCD comes as a complete assembly and is quite difficult to wire something in there.

    My second choice would be to buy a small LED driver with AC input and tap power from something that had 230vac internally. I could draw power from the incoming wall power but that would mean the LEDs would be always on. It should come on only when the machine was powered up.

    I've been trying to search in vain for some bes900 electrical/circuit/wiring diagram on the net but can't find anything. Anyone else has tried to do this or know their way around the machines guts?


  • #2
    If anyone can help or point my in the right direction, I'd be happy to put up some pictures and instructions on how I did it


    • #3
      Bes900 LED modification

      With my Silvia I had to put a 240-12v step down power supply in it


      • #4

        When did you buy your BES900?

        I was one of the first to buy my 900 in August 2011.

        The extended warranty on the BES900 is for a 2 year repair guarantee which for me runs out in August 2013.

        Contact and Support

        How come your machine is out of warranty?



        • #5
          Hi guys

          Ok to clarify. I got the machine in oct last year. BUT i live in Singapore so I don't think I enjoy any warranty (unless I want to contend with expensive freight). I'm quite handy with electronics so am willing and comfortable to tinker around the inside.

          I have bought 12vdc led assemblies which I can connect to some 12vdc that might be around inside the machine (if only I had a circuit diagram!) or I can buy a 230vac led driver to connect to AC inside the machine. I can connect to the 230vac incoming but this would mean that the led's would always be on even if the machine were turned off. I could add a separate power switch for the LEDs but don't want to add an extra switch. I'd rather it worked when the machine came on and turned off together with the machine.

          If the led's could be wired to behave like the power switch light (pulsing when in standby) that would be great but the LCD/power assembly is quite compact and enclosed in its own plastic housing.



          • #6
            Just some ideas,
            Since you are comfortable with tinkering inside, and don't have a circuit diagram, are you able probe a multimeter at various circuits to check for suitable voltage?
            What type of main switch is it? Does it have a spare set of poles or can you replace it with a different switch with additional poles? What about using the original switch to drive a relay, then let the relay do additional switching?
            I'm sure it can be done, depends how far you want to go with it.


            • #7
              There is a LED lighting the water tank from within when the machine is on - could this be a way?


              • #8
                Just a few quick thoughts. Probably the main things to consider here are:
                • Driving your new string of LED's - how much current do they draw and can any supply you tap off inside the machine actually handle the extra load?
                • Ease of implementation.
                • Safety - it's a mains appliance but it sounds like you can probably handle it.

                I think the only way to be sure you're not going to overload something internally is to provide your own supply for the LED's. So your own power supply internally, maybe tapped of the incoming 230V.

                In terms of operation, here's a couple of ideas:
                1) As Raymond mentioned - likely the easiest will be the water tank LED. Find out what its operating voltage is, and use it to turn on a MOSFET to drive your new LED's. No chance of drawing excessive current and there wouldn't be much for the interfacing, maybe a of couple of caps for RF decoupling.
                Simple to implement, switches on and off when the machine does. But won't switch off when in standby.

                2) As above, but use the LED lighting from the instrument panel.
                Might mean more disassembly. Lighting will follow the instrument cluster including doing the nice switch off when not in use bit.
                You could have it do the "fading" if you connect to the Power LED but that would require more work on the interfacing... If you use a basic MOSFET switch your LED's would likely blink on and off. That'd drive me nuts .

                3) Trigger off the supply to the pump, use a delay circuit (or microcontroller) to hold the LED's on for a few minutes afterwards.
                This is the more involved option and would require more significant interfacing design. Throwing there for you to think on as it all depends on which things are easier for you to get to and how the extra wiring might route internally.

                And I guess you'll also need to drill a hole somewhere for the wires to run to the LED's...


                • #9
                  Heh. Another option is to trigger off temperature. Mount a sensor on the boiler, use that to turn on the LEDs when its hot. Avoids using the internal wiring entirely aside from your own power supply.
                  Heck, you could probably buy a kit. Or a quick microcontroller based design would give more control over the hysteresis (plus you get to say your lighting mod is microcontroller based).


                  • #10
                    Or geht a LED lamp on a gooseneck string mount the base behind the machine and bend the lamp head besides the brew head. Presto.


                    • #11
                      Or one of those stick-on LED cupboard lights (actually, might do that myself). I get the feeling the OP isn't after the simple solutions .


                      • #12
                        Hi guys,

                        thanks for all the ideas so far. some quick ideas:

                        1. the led string i have is very small and setup to run off 12vdc. current draw is quite small so i don't think it'll strain any power supplies. The water tank LEd is probably 3v so may not be able to run off it. Using it as a switch sounds good. will explore that idea a bit more when i have time to tinker.

                        2. lcd panel idea is nice but it's all done as a PCB where everything is built really tightly. don't think my skillset and eyesight extends to surface mounted components yet

                        3. gooseneck is too easy also, the undersurface of the grouphead is quite curved so it can only take short lengths of LED's.

                        Thanks again for the ideas. I'd welcome more comments to get the brainjuices flowing.


                        • #13

                          An update. I took a picture after attempt 3 when it briefly worked beautifully.

                          I finally had to to open and work on the machine today. What I had on hand when starting the project was:
                          1. solid state relay, input 3-32vdc, output 24-380vac
                          2. Strip of warm white led's that ran off 12vdc
                          3. LED driver, 240vac input, 12vdc output 630mA

                          First attempt
                          was to use the solid state relay and have it switched on and off by the power button led. Went through the trouble of opening up the assembly and wiring up the relay to the Power switch LED lights. Only to discover they were 2.7vdc when on...

                          Second attempt
                          Measured the contacts off the active cup warmer circuit attached to the top cover of the machine. Wow, 230vac! Thought it would be ok to connect the LED driver to the warmer so that lights would come on when ever the machine was warming the tray. BUT somehow, the circuit receives 230vac all the time, whether the machine was switched on or not....

                          Third attempt
                          Connected the LED driver directly to the ULKA vibe pump so that the lights would come on when pulling a shot or running water. Everything checked out this time. EXCEPT, after the first time I ran the pump, the pump would not switch off!!! The solenoid still worked fine and controlled the flow of water properly except now the pump runs continuously. I thought it might be trying to fill the boiler etc but nope, the pump is still running no matter what. I've now disconnected the LED driver but the pump still runs whenever the machine is turned on at the power button.

                          Any ideas? Did I break my machine? My brain is maxed out and I probably will stop for the day

                          I just opened the machine again to check that the hot water limit switch was not triggered accidentally. it was not so im out of ideas at the moment.
                          Attached Files
                          Last edited by Allywee; 13 December 2012, 10:58 PM.


                          • #14
                            Cool mod but bugger about your side issues. I was thinking of doing something similar to my Faema.

                            Do you have a pic from underneath?

                            If you want to use one of the machines LEDs to trigger your circuit, you could use a kit from Jaycar Electronics (item B197), it can be driven by an LED and turns on a relay, seems perfect for your situation.



                            • #15
                              ok, here is a picture of the underneath where i stuck on the LED's

                              also included a picture taken from google images that looks like the led driver i used
                              Attached Files