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| Subject: From: Date: | Re: [ECS] micro-redac and relays Dan Carrington Mon, 04 Jan 1999 19:09:46 -0800 |
Another thought, if you continue the same way you currently are with more inputs, one powered input may loop through another power supply and drive multiple inputs at one time. Dan Carrington Dan Carrington wrote: > > Yes. If you ever hook another digital input the same way, you are > co-mingling multiple power units on a common hookup on the micro-redac. > Use the transformer on the back of the receiver to drive a relay stuck > to the side of it. Then use the switched side of the relay to switch > power to the micro-redac from one REGULATED power supply at the > micro-redac. This power supply at the micro-redac can be switched into > all 8 inputs without any multiple power supplies being commoned > together. That way you can also use plain old switches as other digital > sensors with the same regulated power supply at the micro-redac. Make > sure to use a regulated power supply at the micro-redac end to keep from > having problems and quirks. > > The way you have it, will work for one digital input without problems, > but more can cause troubles and possibly hazards. By the way, the > resistor is supposed to be between the positive and negative, not inline > on the way to the micro-redac. Parallel, not serial. It is intended to > bleed off the spare power stored within the power transformer after AC > power is removed. > > Parallel > |----resistor-----| > pos----| |------neg > |----microredac---| > > Serial > pos---------resistor-------microredad--------neg > > Hope this helps > > Mark Sekelsky wrote: > > > > Dan, > > > > Here is what I am doing: Currently the only thing I am using the Redac for > > (beyond PLC) is this setup. The transformer is plugged into the back of the > > receiver. The positive wire goes to an in-line fuse (.25 amp) then to the > > resistor (1K) then to terminal post # 1 on the Redac. The negative wire > > goes straight from the transformer to the Redac (post #10). It sounds like > > you are saying this is NOT a good setup? > > > > Mark S > > > > -----Original Message----- > > From: Dan Carrington [mailto:dc_grafx@microworks.net] > > Sent: Monday, January 04, 1999 7:22 PM > > To: ecs-list@netbloc.com > > Subject: Re: [ECS] micro-redac and relays > > > > No. The diode is to to backwards across the coil to short induced > > spikes when the coil lets go of the relay. It would not do anything if > > across the switch side, unless you put it in the wrong way at which > > point it would completely short the power supply. My concern when I > > posted the info, is that I wonder how you use multiple digital inputs if > > you are feeding them with different wall warts (power transformers). > > Are you commoning them into the common side of the digital inputs? If > > so, that could be dangerous!!! For safety, you should use one common > > power supply for all inputs and just switch it into the inputs, which > > solves the problem of delay with capacitor equipped wall warts. > > > > Dan Carrington > > > > Mark Sekelsky wrote: > > > > > > David & Dan, > > > > > > Sorry to take so long to get back regarding your continued suggestions on > > my > > > Redac and receiver. Spent the weekend shoveling out from all the snow and > > > had no phone service at all on Sunday (: A couple more questions (I don't > > > promise that they are the last <g>) if I may. Both of the most recent > > > suggestions are a little over my head, although I am sure I could > > eventually > > > figure it out. So question number one is: > > > > > > What if I just leave everything the way it is? While not excited about > > the > > > 9" delay in changing the state to HIGH it is not a big deal. The big > > reason > > > that I want to check power is that neither the IR Master nor a HV that I > > > played with have been able to control my receiver 100%. My event already > > > incorporates a delay on and off timer so that I can resend the signal if > > the > > > state of the receiver isn't changed. I was using a 6" delay to test for > > OFF > > > but all I have done now is increase it to 12." Even if my response time > > is > > > instantaneous I will incorporate some type of delay check. > > > > > > Question number two. Could I take the diode that Dan recommends and > > attach > > > that to the Redac in my existing system? > > > > > > Mark S > > > > > > -----Original Message----- > > > From: David Mccoll [mailto:dmccoll@intergate.bc.ca] > > > Sent: Friday, January 01, 1999 8:36 PM > > > To: ecs-list@netbloc.com > > > Subject: Re: [ECS] micro-redac and relays > > > > > > Mark S, > > > The transition should be spontaneous with no delay at all. You have a good > > > point about the residuals in the power-pak. There must be a capacitor > > inside > > > the power-pak. You can bleed the stored energy off with a resistor > > connected > > > across the two leads before the digital input of Redac. I suggest placing > > > the resistor before the fuse and resistor for the input. > > > > > > Start with a 2.2kOhm and move down until you get it working well. Check > > how > > > hot the resistor gets with the receiver on. When the receiver is on, the > > > added resistor will dissipate the energy and get hot. This is ok but if it > > > gets too hot it can be a hazard. If the resistors are 1/2 Watt then they > > can > > > dissipate 1/2 Watt max. A 1/8 Watt resistors will be a little small for > > the > > > job. You can halve the heat through the resistor by using 2 resistors in > > > parallel but you MUST double the value of both resistors when you parallel > > > them. This shares the load between them. When you are finished you may > > want > > > to spring a couple dollars for a 5 Watt ceramic resistor. > > > > > > I figure a good value would be 500Ohm across 12Volt = .024Amp and .28Watt. > > > A 1 Watt will do, and a 5 Watt is more than adequate. If you want to use > > > other values you can use the Ohm's Law calculator at this url: > > > > > > http://webhome.idirect.com/~jadams/electronics/ohms_calc.htm > > > > > > DAvid M > > > > > > -----Original Message----- > > > From: Mark Sekelsky <Mark@sekelsky.com> > > > To: ecs-list@netbloc.com <ecs-list@netbloc.com> > > > Date: Thursday, December 31, 1998 4:16 PM > > > Subject: RE: [ECS] micro-redac and relays > > > > > > >David, > > > > > > > >Thanks for the resistor lesson. The 2.2 didn't work but the 1K sort of > > > >does. With only a fuse in place there is about a 3-4" delay before the > > > item > > > >state changes to HIGH. I assume this is residual power in the > > transformer. > > > >With the 1K resistor in place that delay is 8-9" but it does change to > > HIGH > > > >100% of the time. I can certainly live with this but wonder if it means > > I > > > >should be trying yet another resistor or not. > > > > > > > >Happy New Year! > > > > > > > >Mark S > > > > > > > >-----Original Message----- > > > >From: David Mccoll [mailto:dmccoll@intergate.bc.ca] > > > >Sent: Wednesday, December 30, 1998 4:13 PM > > > >To: ecs-list@netbloc.com > > > >Subject: Re: [ECS] micro-redac and relays > > > > > > > > > > > >Mark S > > > >Your connections sound correct. Get it to work 100% before you add the > > fuse > > > >and resistor. If the 10K resistor gives you trouble move down to a 4700 > > > that > > > >is a Yellow, Violet, Red, Gold. If that does not work then move down to a > > > >2.2K or 2200 which would be Red, Red, Red, Gold. If that does not work > > then > > > >go to a 1K or 1000 which is Brown, Black, Red, Gold. > > > > > > > >Originally you said the power pak was 5V DC 150mA. What are you using now > > ? > > > > > > > >Here is some gunk on resistors. This is very simple stuff but on the > > > surface > > > >it may look complicated. The Gold band is what is referred to as the > > > >"tolerance" of the resistor and is usually the last band. > > > > > > > >Gold is 5% -- most common tolerance > > > >Silver is 10% -- not too common > > > > > > > >The first 3 bands are the value. Here is the way I learned to calculate > > > it. > > > >Bad --- Black -- 0 -- .0 > > > >Boys --- Brown -- 1 -- 0 > > > >Rape --- Red -- 2 -- 00 > > > >Our --- Orange -- 3 -- 000 > > > >Young --- Yellow -- 4 -- 0000 > > > >Girls --- Green -- 5 -- 00000 > > > >But --- Blue -- 6 -- 000000 > > > >Violet ---- Violet -- 7 --0000000 > > > >Goes --- Gray -- 8 -- 00000000 > > > >Without -- White -- 9 -- 000000000 > > > > > > > >The first 2 bands are the value and the third band is the multiplier > > which > > > >is the number of 0's to add after the value. So 4.7 K.Ohms = 4700 Ohms = > > > >Yellow, Violet, Red and Gold for the 5% tolerance. The 10KOhm resistor > > > would > > > >be Brown, Black and Orange the multiplier is usually assumed to be 5% > > Gold. > > > >A 100 Ohm resistor is Brown Black Brown and a 10 Ohm is Brown,Black, > > Black > > > > > > > >Keep up the good work. > > > > > > > >DAvid M > > > > > > > > > > > > > > > >