MP Posted April 5, 2006 Report Share Posted April 5, 2006 You should check the data sheet to see if the chip has the accuracy you need. This is a simple matter of research and you should do this yourself.MP Quote Link to comment Share on other sites More sharing options...
Wiggle Posted April 5, 2006 Report Share Posted April 5, 2006 Hi everyone,I'm building this Voltmeter together with the supply 30V-3A from the projects.Now I have some questions about it:1) How can I supply the voltmeter if i'm using a transfo with only one secundary from the dc supply? If I put a voltage regulator 7905 behind it, can I messure the output voltage correctly then?2) If I use the schematic out of the datasheet from the icl7107 i can' t get the correct voltage on my display. I can regulate it to 0 at 0V but I can not get the correct output from a input voltage.I hope someone can help me out with this,Greetings Wiggle Quote Link to comment Share on other sites More sharing options...
cynicmonster Posted May 4, 2006 Report Share Posted May 4, 2006 Hi All,Just looking for some confirmation on a couple of things:1. I'm looking at running this meter from a wall pack - I assume I still have to regulate the power (i.e. can't just stick a zener in there) as the wall pack may not be regulated;2. Do I need to do anything to regulate current - that is, if the wall pack is rated 9v 500ma, will the regulator take care of the current?3. The meter will only be reading +ve voltage, but if I'm going to the trouble of putting it together, I might as well put the -ve supply in as well (protection from wrong connection)...4. If putting in the -ve supply, should I look at using a 12v wall plug?Thanks,Monster :) Quote Link to comment Share on other sites More sharing options...
MP Posted May 4, 2006 Report Share Posted May 4, 2006 Hi everyone,I'm building this Voltmeter together with the supply 30V-3A from the projects.Now I have some questions about it:1) How can I supply the voltmeter if i'm using a transfo with only one secundary from the dc supply? If I put a voltage regulator 7905 behind it, can I messure the output voltage correctly then?2) If I use the schematic out of the datasheet from the icl7107 i can' t get the correct voltage on my display. I can regulate it to 0 at 0V but I can not get the correct output from a input voltage.I hope someone can help me out with this,Greetings WiggleCould you please post a drawing or explain a little more?MP Quote Link to comment Share on other sites More sharing options...
MP Posted May 4, 2006 Report Share Posted May 4, 2006 Hi All,Just looking for some confirmation on a couple of things:1. I'm looking at running this meter from a wall pack - I assume I still have to regulate the power (i.e. can't just stick a zener in there) as the wall pack may not be regulated;2. Do I need to do anything to regulate current - that is, if the wall pack is rated 9v 500ma, will the regulator take care of the current?3. The meter will only be reading +ve voltage, but if I'm going to the trouble of putting it together, I might as well put the -ve supply in as well (protection from wrong connection)...4. If putting in the -ve supply, should I look at using a 12v wall plug?Thanks,Monster :)You should not have the problem of current limitation needed, but others who have built this circuit have complained about the display numbers being a little unstable without real good regulation on the power supply. I recommmend bypass caps at the very least.MP Quote Link to comment Share on other sites More sharing options...
cynicmonster Posted May 10, 2006 Report Share Posted May 10, 2006 Thanks MP,I figure I'm on the right track then. Quote Link to comment Share on other sites More sharing options...
pacermike Posted May 13, 2006 Report Share Posted May 13, 2006 Hi guys,I read through all 17 pages of this thread and almost found what I was looking for. A guy asked how you could convert this voltmeter to read millivolts instead of volts but I think the question got lost in the fray because an answer never came up. I read about shunting for reading higher values but it sounds like this won't work backwards for reading smaller values, am I right? If that's the case then what would I need to do to get a reading in millivolts instead of volts?p.s. I'm the newest kind of newbie so thanks for any help! Quote Link to comment Share on other sites More sharing options...
Tristable Posted May 13, 2006 Report Share Posted May 13, 2006 Everybody, Hello!I'm building power supply from this great community. (looks familiar?)And yeah, I want to add this meters in my PS.So, I have 2 questions:1. As I need only measuring positive voltages, I will use just positive 5V supply. And as my meter will be set on 0-200V range (with 0.1 V precision), and as I do not need negative sign, can I just remove one 7-seg. display - it would be off anyway? Of course, brightness resistor would be bigger.2. Is original PCB layout OK? I hope that one who made Eagle layout is not angry, I appriciate his effort, but I realy dont like boards with askew components. ::) Well, maybe I remove negative voltage generator and make this resistors straight.Thanks, Triple Quote Link to comment Share on other sites More sharing options...
kentlee Posted June 14, 2006 Report Share Posted June 14, 2006 Hello!! Everybody. I am a new member and I want to use this circuit to measure AC voltage around 300V to 400VAC.Can some one let me know which rectifier circuit can be used??Thanks a lot!!! Quote Link to comment Share on other sites More sharing options...
faizanbrohi Posted July 7, 2006 Report Share Posted July 7, 2006 Hello Can i use the Eagle Version of this voltmeter is it ok to build Quote Link to comment Share on other sites More sharing options...
cynicmonster Posted July 7, 2006 Report Share Posted July 7, 2006 Hi Moderators,Well, there has ben a lot of inquiry about this voltmeter.I am truly a Newbie in this field, but can someone PLEASE fix this project so it is an easy project/downoad.Coupled with the power supply project (30v 2a). it is pretty obvious that ppl want this want this project to complete their unit.Can someone please supply an updated schem with voltmeter in order to finalise this project. I too have got the eagle version and am waiting confirmation that all is correct. Quote Link to comment Share on other sites More sharing options...
MP Posted July 7, 2006 Report Share Posted July 7, 2006 There is no guarantee on any schematic you find on the Internet. That is why there is a discussion area for Q/A of the projects in our project section. Most projects which have a substantial conversation thread will also have a link from the project page. The Eagle version is ok. Also, I am pretty sure corrections in the original project were already made my mixos. This should be clear if you read through the pages of this thread. I uploaded the Eagle version so that members who wanted to make a board had an easier method to do so. As far as your comments about the power supply project, many members have built the original and have had no ill effects. The member who has posted the changes in that forum has not built the device, so I will have to take the word of those who have built it over one who claims to be a theory expert.MP Quote Link to comment Share on other sites More sharing options...
cynicmonster Posted July 7, 2006 Report Share Posted July 7, 2006 Thanks MP,Subtle, but the confidence is there to continue with the project.Thanks again :) Quote Link to comment Share on other sites More sharing options...
indulis Posted July 7, 2006 Report Share Posted July 7, 2006 From a purely analytical standpoint, "the theory expert" does make SOME valid points!! From a practical, "I only have to build one of these, not 10,000...", it probably doesn't matter!! Quote Link to comment Share on other sites More sharing options...
MP Posted July 7, 2006 Report Share Posted July 7, 2006 Sure. I just get tired of the scare tactics to newbies....you will fry this if you don't follow my instruction....etc.. but then I get emails from those who have built the originals with no problems, grumbling about what they feel is a false posting on this forum.Projects Q/A is primarily for those who are actively building these projects. Not for theory statements or overall attempt at re-design in one's head. We have a forum for Theory discussions.Thanks for your input.MP Quote Link to comment Share on other sites More sharing options...
MP Posted July 7, 2006 Report Share Posted July 7, 2006 additional posts regarding theory discussion has been moved to the Theory forum.We were getting a little off-subject here.Thanks,MP Quote Link to comment Share on other sites More sharing options...
faizanbrohi Posted July 12, 2006 Report Share Posted July 12, 2006 Okay this is not a theory discusssion , i have built the ICL7107 voltmeter and is working great , form www.electronics-diy.com , here is the PCB layout and silkscreen. the lines are jumpersThese are the componenets list VALUE SHAPE # REFDES 1.0MOhm_5% R0204R7_5 1 R6 1N4148 DIO_DO35 3 D1,D2,D3 10K_LIN TRIPOT10X5V 1 R2 10kOhm_5% R0204R7_5 1 R5 10nF MKHCON4A 1 C7 10uF-POL ELKO10R5 2 C1,C2 15kOhm_5% R0204R7_5 1 R3 47kOhm_5% R0204R7_5 1 R4 100kOhm_5% R0204R7_5 1 R1 100nF MKHCON4A 1 C4 100pF KERKO5X4R5 1 C3 220nF MKHCON4A 1 C6 470nF MKHCON4A 1 C5 DIPSW4 DIPSW4H 1 JSW1 ICL7107 DIP40S 1 U1 ICL7660 DIP8 1 U2 JUMPER JUMPER 20 J1,J2,J3,J4,J5,J6,J7,J8,J9,J10,J11,J12,J13,J14,J15,J16,J17,J18,J19,J20SEVEN_SEG_DECIMAL_COM_A 7SEG8DIP14B 4 U3,U4,U5,U6 TEST_PT1 PB 4 GND,INneg,INpos,VCCICL7107.rar Quote Link to comment Share on other sites More sharing options...
faizanbrohi Posted July 12, 2006 Report Share Posted July 12, 2006 The PCB artwork and layout , sorry for too many jumpers. but the thing is this panel meter was for something else then measuring voltage , i am actually calculating length from it . i will post the full project when it is complete Quote Link to comment Share on other sites More sharing options...
gogo2520 Posted July 14, 2006 Report Share Posted July 14, 2006 Hello Someone was asking about the board that someone drewup in eagle. i looked at it and almost made it, went so far as to burn the board. I think that it isn't right. looks like the 7 segments are backwards.Don't know has anybody eles tried it. I'll post the files so you can look at em. gogoICL7107.zip Quote Link to comment Share on other sites More sharing options...
MP Posted July 14, 2006 Report Share Posted July 14, 2006 It's a double sided board. I think you are trying to mount them on the wrong side.MP Quote Link to comment Share on other sites More sharing options...
gogo2520 Posted July 14, 2006 Report Share Posted July 14, 2006 Hello MP I know its a double sided board, what I think I did is burned it upside down. I think. I am doing heat transfers so I burned the printed the bottom and mirror the top and then printed. Don't know maybe I should of mirrored the bottom and not the top. guess I will have to stare at it for awhile gogo Quote Link to comment Share on other sites More sharing options...
MP Posted July 14, 2006 Report Share Posted July 14, 2006 Don't stare at it too long.... ;DAs I understand it, the dots will start to connect.MP Quote Link to comment Share on other sites More sharing options...
gogo2520 Posted July 14, 2006 Report Share Posted July 14, 2006 hahaha Ya MP thats what I think my problem was to begin with. Heres what I come up with. I mirrored the bottom layer and just printed the top. seems that works. I printed it out and played with it. Makes since that way. time to burn another board. have fun gogo Quote Link to comment Share on other sites More sharing options...
gogo2520 Posted July 16, 2006 Report Share Posted July 16, 2006 AH BOO WHO :'( that way won't work either, makes the L7660 backards. I would use the original project but Iwant to put a L7660 right board too. Oh well back to the drawing board.Hey MP someware on this said there was a schmatic posted on the eagle web site, I coulde find it. You wouldn't happen to have a copy of it ::) have fun gogo Quote Link to comment Share on other sites More sharing options...
gogo2520 Posted July 18, 2006 Report Share Posted July 18, 2006 Hello MP the eagel pcb you posted don't work unless you drill holes throuth the 7107 to get the 7 segments to place right. Thanks anyway back the the org. have fun gogo Quote Link to comment Share on other sites More sharing options...
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