audioguru Posted May 30, 2005 Report Share Posted May 30, 2005 Hi Pieter,Sure, the pickup coil picks-up magnetic pulses from your monitor too. Thanks for letting us know. ;D Quote Link to comment Share on other sites More sharing options...
pieterw0 Posted May 31, 2005 Author Report Share Posted May 31, 2005 Hi Audioguru A small problem. I need to change some resistor values in the warning part of the circuit.(Old circuit) When I set R11 to 47K it moans on 1000 rpm. When I adjust R11 to 0 the highest revs I get is 1500 rpm. I need to gain at least another 2000 rpm. Because I cant go further than zero I assume that lowering some resistor values, would do the trick.So I’m not sure which ones.Any suggestions as to what resistors I could change.ThanksPieter Quote Link to comment Share on other sites More sharing options...
audioguru Posted May 31, 2005 Report Share Posted May 31, 2005 Hi Pieter,In the original project, didn't you remove R10? It scales-up the RPM range a little.I think R11 could be adjusted for higher RPM's if you reduce the value of R12 maybe to about 27k. Then the setting of R11 would be very sensitive near zero ohms so should also be reduced to about 20k.Instead of changing all those resistors, try 47nF for C3. ;D Quote Link to comment Share on other sites More sharing options...
pieterw0 Posted May 31, 2005 Author Report Share Posted May 31, 2005 Hi AudioguruIn the right up the author sugested the following.Depending on the engine's cylinders number, R11 can be unable to set the device properly. In some cases you must use R11=200K and R12=100K or less. I did follow his advice but with with little change. So I thought I could make changes somewhere else. With your advice I have more room for improvement. The thing is that I don't want to tamper with components that might afect others. Thus causing more harm than good.I will try your advise and let you knowThanksPieter Quote Link to comment Share on other sites More sharing options...
pieterw0 Posted June 1, 2005 Author Report Share Posted June 1, 2005 Hi Audioguru What is wrong with this picture.This is a Make before break single pin select switch. This configuration means the values of the 4 pots. Is there a different way of doing it or should I rather get a switch that select 2 pins simultaneously so that each pot could be selected individually? ThanksPieter Quote Link to comment Share on other sites More sharing options...
audioguru Posted June 1, 2005 Report Share Posted June 1, 2005 Wire the pots with one side of them connected together like this: Quote Link to comment Share on other sites More sharing options...
pieterw0 Posted June 1, 2005 Author Report Share Posted June 1, 2005 Hi AudioguruThe black lines does represents the connections as you sugest. The switch also selects each pot individually. What happens is that instead of each (SELECTED) pot adjusting between 0 and 100K, each selected pot adjust only between 55K and 85K. It doesn't go to zero and it doesn't go to near 100K.How ever, If I only use ONE pot the adjustment goes between 0 and 100KThis is what I mean that it means (averages) the valuesPieter Quote Link to comment Share on other sites More sharing options...
audioguru Posted June 1, 2005 Report Share Posted June 1, 2005 Each 100k pot should adjust from zero ohms to 100k ohms. Maybe your reduced range is because R12 is in series with it and R10 is in parallel with both in series. Quote Link to comment Share on other sites More sharing options...
pieterw0 Posted June 4, 2005 Author Report Share Posted June 4, 2005 Hi AudioguruSorted it out THANKS!Who made electronics so complicated anyway? ;DPieter Quote Link to comment Share on other sites More sharing options...
pieterw0 Posted June 4, 2005 Author Report Share Posted June 4, 2005 Audioguru I meant to ask you. I have the project working in a way.With this unit working on rpm it should warn on what ever revs are set.In my car the unit is set for 2000rpm which represents approximately 60 kph. When you pull away from stand still in first gear the revs reaches 2000rpm. Switching to second gear, before changing to third gear it reaches 2000 rpm. So whilst changing gears the alarm sounds every time the revs reaches 2000rpm.My question!!!!!!!!!!!!!!!Is there a way that one can delay the alarm if the revs changes irregularly?Or is there a way to make the unit respond ONLY when the revs has stabilized?Any ideas to take the annoying beeps away whilst changing gears would be appreciated.ThanksPieter Quote Link to comment Share on other sites More sharing options...
audioguru Posted June 4, 2005 Report Share Posted June 4, 2005 Hi Pieter,It ain't complicated and it ain't a speed-limit alert. It's an RPM alert! ;D ;DIf you want a speed sensor then drag a 5th wheel behind your vehicle.Or you could hookup something to your ABS sensors.You could slow the circuit's response time by increasing the value of the 1uF capacitor at pin 4 of the LM2917. Then it might be so slow it will drive you crazy! ;D ;D Quote Link to comment Share on other sites More sharing options...
pieterw0 Posted June 4, 2005 Author Report Share Posted June 4, 2005 AudioguruIt is a speed alert. you called it a long distence speed alert. ;DI think I will settle for the 5th wheel. ??? ;D 8)Any ideas what size?Pieter Quote Link to comment Share on other sites More sharing options...
ante Posted June 4, 2005 Report Share Posted June 4, 2005 Hi Pieter,It’s easy, you need a sensor for one of the drive shafts (if a front wheel drive) or the driveshaft if rear wheels drive! This way you are measuring the speed and not the RPM which is not related to the speed since you have more than one gear. 8) Quote Link to comment Share on other sites More sharing options...
pieterw0 Posted June 4, 2005 Author Report Share Posted June 4, 2005 Hi AnteI was actualy playing around with audioguru and the 5th wheel. As you might have noticed from his posting that in my opinion I think he was sarcastic. So I humored him.Anyway I was looking at magnetic sensors as well as reflective laser pick up's that works on a shaft. (Prop shaft or drive shafts).There is a variety of sensors (pick-up's) available. If one would go for the magnetic version then you would need something like a belt with magnets evenly spaced to go around the shaft. With the laser, you would need a piece of tape with black markings evenly spaced around the shaft.http://www.shumatech.com/dro-350/add-ons.htmhttp://www.jeffree.co.uk/Pages/speedmeasurement.htmlI still think it is posible to change a component value to slow the response time in the original circuit to avoid the anoying beeps. . . . . . . . . . ;DI would welcome any suggestions.Pieter Quote Link to comment Share on other sites More sharing options...
ante Posted June 4, 2005 Report Share Posted June 4, 2005 Hi Pieter,Yes I could see he was teasing you but my point was the problem of using the engine rpm for this purpose. The two links you provided are interesting and useful but I think maybe these types of sensors are too sensitive to work under your car. They will be exposed to all kinds of dirt and moist from the car itself and from the road. I would use an inductive sensor and a small piece of metal (or a number of like a cog, if more pulses are required) attached to the shaft. Inductive sensors are better suited to “live” in this environment. 8) Just a suggestion. Quote Link to comment Share on other sites More sharing options...
pieterw0 Posted June 5, 2005 Author Report Share Posted June 5, 2005 AnteYou got me very interested in your suggestion. The small piece of metal, is this attached to the shaft with the inductor a few inches away?Could you give more info as far as the specs of the inductive sensor. Perhaps if you have something on this type of configuration I would be happy to try it.ThanksPieter Quote Link to comment Share on other sites More sharing options...
audioguru Posted June 5, 2005 Report Share Posted June 5, 2005 You could slow the circuit's response time by increasing the value of the 1uF capacitor at pin 4 of the LM2917. Quote Link to comment Share on other sites More sharing options...
ante Posted June 5, 2005 Report Share Posted June 5, 2005 Hi Pieter,Yes but not as far away as a few inches, more like a few millimetres! Somethin like this is what’s needed: http://www.elfa.se/elfa-bin/dyndok.pl?dok=7293.htmThis is just an example, there are many similar out there! Quote Link to comment Share on other sites More sharing options...
pieterw0 Posted June 5, 2005 Author Report Share Posted June 5, 2005 AudioguruI am still on the old circuit. (Original) Pieter Quote Link to comment Share on other sites More sharing options...
pieterw0 Posted June 5, 2005 Author Report Share Posted June 5, 2005 Thanks for the feedback tnk2k and AnteI will scratch around a bit and see what I can come up with.Pieter Quote Link to comment Share on other sites More sharing options...
audioguru Posted June 5, 2005 Report Share Posted June 5, 2005 You can slow down the response time of the original circuit by using two 10k resistors in series for R18 and adding a capacitor to ground at their junction. Try 100uF to 1000uF. ;D Quote Link to comment Share on other sites More sharing options...
pieterw0 Posted June 5, 2005 Author Report Share Posted June 5, 2005 Thanks! ;D Quote Link to comment Share on other sites More sharing options...
MP Posted June 6, 2005 Report Share Posted June 6, 2005 Pieter,I suggest you continue to try contacting the author. I have e-mailed him a number of times and have had no problem with replies after a few days. Perhaps he is on holiday. In a past conversation, Red has told me all of the projects he posts on his site have been bench tested.MP Quote Link to comment Share on other sites More sharing options...
pieterw0 Posted June 10, 2005 Author Report Share Posted June 10, 2005 Hi MPThanks for the adviseI got it working in a way.Pieter Quote Link to comment Share on other sites More sharing options...
Mandavar Posted January 2, 2007 Report Share Posted January 2, 2007 Hi all Anyone here can help me with the operation of IC3 (Dual Monostable multi vib)i really need to understand the full operation of this IC in the Wirless Speed Limit alert circuit ... Thanks for help in advance Quote Link to comment Share on other sites More sharing options...
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