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About AGS

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  1. AGS

    Converting Voltages

    Hi thanks Kilrah the 8V device is a TX which I ripped out of an imported CMOS camera from HK. The current draw I measured is around 26mA at 8.11V using a multimeter and a regulated power supply to power the TX. Funny though I tested in the workshop and I was getting an image on the TV from the camera when it was plugged into the TX but it was really bad (like a badly tuned camera) it seems the TX could work from 4V to 8V still transmitting an image but the change in voltage slightly altered the frequency I guess. I have to stress though I am using a T450 V2 and I cant imagine carrying two 11.1V lipos but true you do have a good point, I am just trying to do with what I have since a battery would set me back at least £20. But as I have seen its not as simple as stepping it down to 5V then DC-DC up to 12V, it does work but as soon as you start adding (load) devices e.g camera (100mA), TX (26mA), audio amp (20.5mA) the voltage readings drop, but im suspecting it is the DC-DC converter because it is rated 1W with 84mA-AT-12V. BTW 20.5mA is tiny, I dont expect the battery output to give up and take 6V because of that one device. I need to get 12V regardless of devices attached. Thanks Ayo. P.S and eickst I dont think I can get hold of that convertor in the UK, the online store I am using is here. Can anyone recommend anything similar or better because I find choosing the right one confusing. Thanks a bunch guys.
  2. AGS

    Converting Voltages

    Terry I really think it might be the current drain, I guess voltage doesnt work like I thought it would. I feel like giving up, people are saying use this and use that but I dont have many resources like some guys in the US. I have been using yahoo answers and the guys over there say: "powering 4 devices from one battery?" YOU ARE USING BATTERY? my ans is out of topic..yes you can build a voltage regulator using transistors, but the more you add passive devices like resistors, the more you waste across that resistor considering that your supply is only a battery to power-up those 4. Batts are good source of pure DC and for experiment, to achieve an ideal result, but it can not sustain multiple loads drawing current at the same time..Just build a basic transformer supply. Look fo IC's with 4 outs as regulator, you may spend less and save time" and... "you need to build yourself a linear regulator!! you lose regulation by dropping voltage across the resistor, as your demand on the supply goes up, you lose regulation. Copy the linear regulator in the ASTRON 12v 35a power supply (schematics at www.repeater-builder.com). it uses a stable LM723 IC and 2N3055 pass transistors" The problem is I order my parts from this website (click here), does anyone know what IC's etc I should order?
  3. AGS

    Converting Voltages

    Thanks for the answers guys, I have been given more time, I now have until tuesday for my final deadline for a presentation. OK, I have made a circuit that consists of an ESKY 7.4V lipo 800mA (2s) being stepped down to 5V using a resistor in order for a DC-DC converter to step it up to 12V. I have used a DC wire splitter used for CCTV cameras. It converts 1 DC output into 4 DC outputs. I am now getting 12V on all four outputs. However my new problem is that I am going to power a CCD camera (100mA), transmitter (26mA) and audio pre amp (20.5mA) for the mic using up 3 of the 4 wires. But as soon as I connect the audio pre amp the voltage drops down to 8V on all four wires. I have already measured the current draw and it is only 20.5mA so I really dont know what is causing the voltage drop and how can I resolve it so that I get 12V on all 4 wires and solve the voltage drop? Thanks.
  4. Hi there folks, I decided to make a UAV but everything in it has so many different voltages, I have gone with the T-REX 450 as the platform with a Sony 1/3 CCD board. I need a little bit of advice on converting a 7.4V lipo to supply 12V for a camera and pre amp, and 8V for a TX. I know its a bit last minute but I have only three days to do this by for my project. I have already put together a step down converter circuit but if I step 7.4V down to 5V for the DC-DC (fixed to supply 12V with 5V input) up to 12V and then back down to 8V will it still work? Will I lose voltage or current? Also I have already purchased two DC-DC converters CLICK HERE the pdf is also supplied, I just dont know if it will work and what do I need to complete it? Thanks Ayo.
  5. Use a LM317T with 0.1uf and 1uf capacitors. You can use a 260 Ohm resistor and a 4K7 variable. Connect a voltmeter to the output and a 12V input, use the pot on the variable resistor to change output value until you get 7V. You can find the schematic on the net anywhere. Hope this helps.
  6. Hey how did you record your FPV? Also I need some advice on an antenna, the problem is im using it on a cheap built in 50mW transmitter that came with a 'wire antenna' on 2.4Ghz with the advertised range of 100m on the ground I'm making the goof proof patch antenna on the RX end but I dont know how much Im expected to get out of this cheap hong kong import
  7. Hi guys, I have been working on a project putting fpv on a trex 450 and I need to make everything as light as possible. I am going to use a 11.1v battery to power the heli and the camera/tx I have a 2.4 ghz import but according to the 1.2 ghz system here http://www.rc-cam.com/hk_video.htm the tx needs 8v and the camera needs 5v. I have ordered a sony 1/3" CCD to supercharge the video quality but it requires 12v instead of 5v so I need help. I thought about puting in a 8v regulator and letting the camera have the 12VDC (11.1v) direct. But something simple has confused me are the positive and negative wires carried in one where they go into the camera and tx, here http://www.rc-cam.com/imagehkv/cam_rf2a.jpgand also does the regulator (5v?) step down the 9V input into two seperate voltages here http://www.rc-cam.com/imagehkv/vreg1a.jpg is that possible? Any help will be really appreciated thanks.