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i noticed when the supply voltage starts to drop then the sample pulse is no longer in the correct position as decay curve starts to fall...is there a way of making the sample pulse track the decay curve as it changes due to supply voltage dropping ????
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AGAIN??? De Ja Viu?
ne555/tls555 is affected from unstabile drop batt voltage that you see. this is SPECIFYING GENERATOR TX and it power
supply MUST BE VERY STABILE. if you want to get stabile surf you have to think about THE power supply.
i see 2 way.
1. linear stabiliser. like LM7910, 12. you need to supply from 10+2 or 12+2 minimal input batt voltage according.
2. STEP UP converter. input voltage - any. output voltage - stabile 12V. -
The step-up converter is the best method. It's better than 90% efficient and so is easy on battery current and the output is very stable. Also, it is usable until the battery has completely discharged.Comment
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Sounds like your battery is not enough Amp Hour. Try larger battery and maybe a Cap between battery and battery to board.Comment
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i did some experimenting with buck converter and i found the converter draw about 30 to 40ma from the batteries...which is for me a bit high as im only using 800 ma battery pack.Comment
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Hi kt315Originally posted by kt315 View Post
i will try a 12 volt low drop out regulator just to supply the ne 555 as you said.Comment
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What is your stabilized load voltage and how much current does it take?Originally posted by daverave View PostComment
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Maybe you can obtain something like this;
Input: 3-32 V
Output: 5-35 V
Output current: 4 A max (real 3A)
Current draw: 18 mA
Last edited by Qiaozhi; Reason: Abuse
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Hello Dave, your choice is BAD.Originally posted by daverave View Post
you will waste a much in power (batt reserve).
I give you DIRECT LINK http://www.ebay.com/itm/XL6009-DC-Ad...UAAOSw~gRVs4zrComment
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i supplied the 555 oscillator with 12v from reg then i had nothing but problems...the mosfet started to get really hot and my current went up very high...it seems the reg 12v was upsetting the mosfet drive...i had to replace the mosfet and one of the clipping diodes went low resistance...also now my waveform has more ringing but seems to give better depth now under damped.
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If you want to stay with 16V then the step-up converter that kt315 suggested (and that’s the one I use) would suit you. Its efficiency is specified as up to 94%.
16V @ 140mA = 2.24W. Assuming a minimum 90% efficiency your load will take 2.49W from the battery.
Using a single lithium cell with an average half- discharge voltage of 3.6V, the average current would be 690mA. So a 18650 4000mAh rechargeable cell will last for 5.75hrs. If that’s not enough then you can put two cells in parallel to get 11.5hrs. If you decide to go that way then used ‘protected’ cells to prevent over-discharge.Comment
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step up converter will work with input voltage less than 12V needed for surf. so i mean to supply from 1-2 li-ion batts, 18650, 3,6V -7,2V.
this is due i told in http://www.geotech1.com/forums/showt...ighlight=eliteComment
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Yes, either way would work. I suggested that way in case he only wanted to use a single cell.Comment
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Where do you buy them ? never found them with more than a real 2000 maSo a 18650 4000mAh rechargeable cell will last for 5.75hrsComment
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