Xenobius

Hello I have a tiny problem here at my house.... I wish someone could give me a hand ! At my House I have 2 phone lines. My Mothers is 123456 and mine is 987642 My mums line is downstairs and I got the other one upstairs. Is there a circuit that can BOND these 2 together so that when I phone or she phones, it does not interfear but when I press a button, the phone downstair will ring if it is available AND i can talk to my mother (without goind downstairs) also I could actually call her but it would cost money ofcoarse and it is rediculuse to call INSIDE the same house! Thanks

thanks for the reply. the Saturday timer you are mentioning it absolutely not necessary for me because this is just so that i press it and go to sleep! ALSO my problem is that I do not have accesss to neutral wire! only to LIVE wire. The 555 timer you are talking about may interest me! Please inform me! thanks

Hello I would like to stop risking of breaking my legs everyday at night! ;D seriously now .. I have my room lights far from the bed and I hate that so I was wondering if I could make a small SWITCH so that when I press the switch the lights will go ON for 30 seconds and than off again. In other words there would be 2 switches in the wall! ONE for the room lights that would leave the lights on until I press it again (just like normal) and another switch that when I press it, it would activate a relay (IN PARALLEL) to the other switch for 30 seconds. Could anyone help me please? the less components the better since I do not have space in the smal box... also If you could assist me in utilising 230vac instead of transformers etc ... that would be great! .. thanks

could you please guide me ? thanks

Hello I would like to ask a question. I have a circuit which need 2 different voltages. 7.6V and 3.6V. I would like to take the voltages from a PC Power Supply which has 12V and 5V. Which when measured with a multi meter are truly 12v and 5v. My Problem is this. How can I get 7.6V from 12V and 3.6V from 5V (all I want is to reduce the voltage BUT I need 500mA for both. (I do not think I can make a Variable resistor for each because 500mA is a lot. BUT Im not sure anyway. all I want is the 3.6V and 7.6V. Thanks a lot and hope it isn't much.

Thanks mate. Now I want to make an LED flash 5 times for 1 second or 2 when someone passes from inforont the PIR. How can I do that with a Low output (lowoutput from the schematic in the thread above) also Is it possible to make an optional piezo buzzer just in case I find the system not good in the morning and I need sound? I think this would be usefull to everyone knowing you can make an led, (maybe a relay) , and a piezo buzer with it. thanks

Hello I was at the local electronics shop and I bought a PIR (like a transistor with 3 leads and a smal screen on it's head. I would like to build a sensor so that when my neighbours cat jumps inside the house from the window, I would know with the help of an led and a small beep. Could anyone help me please? thanks a lot

Ok I have combined 2 circuits in one and created a PCB for it. I will go buy the components tomorrow and build it. I will post the PCB if you want.

Hello I am going to build the IR Remote Control tester found on the Projects section of this website and I see that in the schematic, you can put a Volt Meter to read the power of the IR. I would like to modify it so that instead of a volt meter, I put 6 leds (2 green, 2 yellow and 2 red) and the more power the ir send the more leds will light up starting from green to red. In other words I would like to add an LED volt meter to it. And since I will be using it with a battery, I would like to make a small slide switch to it so I can either read the strenght of the IR remote or read the bettery life! Thanks a lot

Ok from all the info I am finding, CO2 is included everywere. Prepare a cylinder of CO2 ;D .... seriously now I have order a cd full of LASER plans and stuff.. will continue this topic when the cd arrives and I check it out. till next week I hope many people try to raise a little this topic... Everyone would be interested in a laser cutting system that you can easily build but no one helps you do the research .. ta

Check thi out as well http://www.repairfaq.org/sam/laserlps.htm#lpsnsw9

I found this web site which is very informative and can also lead a lot of people including myself to know what exectly we are looking for http://www.twi.co.uk/j32k/protected/band_3/kspah004.html

I will try to browse the web to find a place were to buy the laser die (the laser EYES were the beam is to be shot) than I guess this forum has technical people enough to help me create a power supply and a circuit to make this baby work.. If ANYONE can help me with finding the die of the laser please do so.. also if it too expensive I will try to work on a water cutter instead of a laser cutter. thanks :D

Hello all I would like to build a cutter for PCBs and I thought I'd do somthing cool with a laser to cut pcbs! Is this possible? thanks

If the LED starts to light, then yes the voltage decreases.

:D thanks you too for your help and all who helped. I am still building the PCB since I had little time but I willl post the results of using a 30vac 5A transformer and post pictures as well like I did in the previus project (which was the same PSU but with the rated transformer. THanks all 4 now

It's ok I already bought the components and lucky for me I bought everything double the wattage. meaning 1/4 ... I bought it 1/2 a watt and so on.. anyways here is the modified PCB (only Q2 package is different) for anyone who is following the thread pcb.zip

Great I am going to modify the PCB for the TIP31A and im off to etch the PCB .... thanks my friend.. one question.. are you 100% sure it will work ? :D thankyou

Is any one working on this mod?

OHHHH BOY ... but filtering and smoothing the ac voltage, wouldn't it go up a little ? passing ac from a bridge and a capacitor will increase the dc voltage. ??? let's assume that they wouldn't give me the current ou mentioned, I still want to make this PSU accept 30vac from the transformer so that I can build it! thanks

But I have a transformer with 4 outputs and 2 of them are: 30Vac 5A (both of them) As you can see I cannot change the transformer because it costs a lot (110 USD) and it was customly made for me. Im stuck with a 30Vac 5A transformer :-\ About the modification to make this circuit work iwth a 30Vac input, what should be done then ? .... boy im way back in technical speaches. :'(

??? I dunno im not that technical. I can only follow a schematic and build it .. I don't know what the circuit would be doing thou. Um .. so you suggest to try and find a circuit that takes 30v transformer 5A? Il try to find something than .. any help would be really appriciated since you are all more thecnical than me. thanks and if there is a post that may confuse someone please let me know so i can modify it / delete it. 10q

I was thinking a little... So you need a 24VAC 3A transformer for the original circuit.. and you need a 30VAC 5A transformer to make it go up to 5A?? When you rectify the 30VAC they would go up to 44vdc !! Isn't 44vdc a lot for the circuit? That is why I reduced the voltage with a regulator!! What are your opinions!

Well as may know I was crying for help on some previous posts... I don't know a thing.. I just passed on what the engineer told me ! he said that if the circuit wants a 24vac transformer with 3 A , than I should change those components to make it take up to 5A and if the transformer is 30VAC instead of the 24VAC you should make a voltage regulator so that you would not have to change the IC's Audioguru.. you told me that the 24v regulator is limiting supply to U2 to 29.6V ... but if you have a transformer of 24VAC would you have the same voltage on U2? (because 24VAC will go up a little after smoothing) About R7, (the current limiting resistor) he told me that it needs to limit 5A now instead of 3A .. so he changed the value to make it limit 5A instead of 3A (somthing like that) About the Capacitor he worked out a sum so that with 5A, there will be the SAME ripple as in the original design and the value of the capacitor was 5500uF but since it's not a standard value he told me to make a 6800uF or else a 4700uF in parallel with 1000uF. About the transformer I did not suggest it mate ... but it was written in red in the project/power section. (PASTE below) Input Voltage: ................ 24 VAC Input Current: ................ 3 A (max) Output Voltage: ............. 0-30 V adjustable Output Current: ............. 2 mA-3 A adjustable Output Voltage Ripple: . 0.01 % maximum About Q2 I did not change anything (I am still waiting for someone on this forum to confirm the changes so that I wouldn't etch a pcb for nothing) but anyways.. should I Upgrade it? ? Hope you reply soon because im on HOlidays and soon will end and wouldn't have time to build it. Thanks for the help both of you Oh and by the way MP ... I don't have a clue how to compare :-\

If by any chance you have a transformer which is 30v and also 5 amps do both the modifications. hope my last 3 posts help all who needed the modification and I would love if anyone would point out any mistake that the engineer has taken ..