# Search results

1. ### Traffic light using ONLY IC 555? is it possible?

555 traffic light Hi... I've got question.. is it possible for us to use only 555 to control 3 LED (Red, gree, yellow). Every LED turn on 1 second, then off. The order is RED= On (1second), Green & Yellow = Off Green=On(1second),RED & Yellow = Off Yellow=on(1 second), RED & Green= Off Is...
2. ### Prepayment Power Metering? Need Help please...

Hi All.... I'd like to build prepayment power metereng for my boarding house(smaal appartment). The Idea is every room has Prepaid power metering like prepaid in mobilephone. Every room buy amount of power. For example room A buy 100kW = \$100 (the price only my illustration). After payment, the...
3. ### 16bit variabel in AT89S51? is it possible? help please

hi all... I have a problem programming old microcontroller type AT89S51. I have two variable a (8bit) and b(8bit), i want to merge it to be 16bit data. the a variable A become upper bit and B variabel as lowerbit. How to merege and store it in AT89S51? Is there any register in AT89S51 that can...
4. ### Adding current source+triangle wave??need help

Hi all... I try to build pulp tester using simple circuit. The Idea is create a current sourcer about 42 mA and add it with triangle wave 130Hz 6v. The problem is how to combine it? using simple adder? If i succes make current source with output 42 mA..then if I add it with the triangle wave...
5. ### How to measure current in high voltage (kV)???help please

how to measure kv hi all, I wonder how to measure current in high voltage power supply without special measure tool?is it possible to use general voltagemeter. because the output about 200 kV(DC). actually, i want to know is the power suply is working. so how to make it measureable using...
6. ### How to measure water flow and its pressure? need your help

how to measure water flow and pressure Hi all, I wonder how to measure water flow in the pipe that buried underground? i want to make tools that can monitoring the velocity of fluid that flow in the pipe and send digital data to PC (real time monitoring)? what kind of sensor that i can use...
7. ### analog PID controller trouble??

Hi all, i try build analog PID controller using opamp, after finished i test it. when input PID is 0V why the output become 10 volt? how to check if my PID it's work? is there any metode to tuning PID? plese give me some reference? thanks PS: i test the plant and it works well. Regards elits
8. ### What is pick up coil methode??

Hi all, is there anyone know about pick up coil[as sensor] methode to take voltage change from ignition cable? Thanks
9. ### Sensor for RPM meter?

motor dc 10.000 rpm indonesia Hi all i've got task to measure RPM for motor dc. the motor has RPM about 10.000 RPM. What kind of sensor i can use? optocoupler or Photodiode or hall effect sensor? to measure high speed RPM?Why? Thanks Regards, Elits
10. ### Capacitor Respon on Oscilloscope?? is it possible??

Hi all, I wonder, is it possible for us to see capacitor respon [charging and discharge] on digital oscilloscope??if it's possible...so how to set it up. Thanks Regards Elits
11. ### How to Converting coaxial cable Impedance from 75 to 50 Ohm?

coaxial cable impedance Hi all, I need a coaxial cable with impedance 50 Ohm. After looking at my local electronic store there is only 75 Ohm Coaxial cable. Is there any way to converting 75 Ohm Coaxial Cable into 50 Coaxial Cable ?? perhaps by adding some circuit?? Please help me. Thanks...
12. ### HOw to simulate control electronic plant ?help please

Hi all, i have task to build electronic plant that reprensetate second order using opamp+resistor+capacitor. before i build i, i try to simulate it using electronic software like PROTEL DXP 2004 and Circuit maker 6.0. Unfortunatelly, the respon like overshoot, error steady state don't appear at...
13. ### how to make electronic plant using opamp+capacitor?

how to make electronic plant ? Hi all, I've got task in control theory system to make simple electronics plant using opamp+capacitor? how to configure it? could someone help me...please Thanks Elits

15. ### second order electronic plant+schematic? please

Hi all... i got project from my control system teacher...he ask me to find simple scematic that represent second order electronic plant. is there anyone that can helpme. please give me some explanation too... thanks regards Elits
16. ### Development of a Control Theory experimental set...how??

hi all, i get project from my teacher to make "Development of a Control Theory experimental set". Truelly what is this? is there anyone could give me reference about it? please thanks regards,
17. ### How to discharge high voltage in tv tube

how to discharge a tv Hi all, Yesterday my color TV getting trouble. I want to check it by my self. But, my friend ever told to becarefull when we repair the TV coz there is high voltage in the tube of TV eventhough we have unplug the main power . Is it true? So, Is there any way to discharge...
18. ### What is the capcitor function????????

Hi all, i'm curious what is the function of Capacitor after diode bridge in power supply. How it work?when the capacitor charge and discharge? my friend ever told me that the capacitor only charged(never discharge). he said that when capacitor start to discharge, it has supplied again by...
19. ### how to build pH meter??

ph meter schematic Hi all, i'll plan to make a pH meter for my school project...but i don't have any idea about how to measeure the pH. is anyone can help me...give me some reference, schematic, or anything...please Thanks Elits
20. ### Need reference about switching the LED? Max frequency?

led switching frequency Hi all, I need some reference about the ability of LED switch on-of?...How max frequency of Pulse Width Modulation that can be apply to LED? Thanks Regards Harish