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Tarik Mokafih's user avatar
Tarik Mokafih's user avatar
Tarik Mokafih's user avatar
Tarik Mokafih
  • Member for 6 years, 10 months
  • Last seen more than 1 year ago
  • Morocco
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Amplify my 3.3V DAC signal to 220V
OptoTriacs may do the trick I guess
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Amplify my 3.3V DAC signal to 220V
Thanks for the answers, I guess I can use Triacs instead of relays, right ?
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Amplify my 3.3V DAC signal to 220V
@DSWG, You don't think it's possible to use step by step amplification (5 times a 50 volt Op amp circuit) ?
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Amplify my 3.3V DAC signal to 220V
@EdgarBrown, Current requirements are as low as 50mA, Frequency as the image explains is 50Hz or less than 1Hz. Thanks
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Amplify my 3.3V DAC signal to 220V
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Amplify my 3.3V DAC signal to 220V
Hi @SpehroPefhany, yes 220V is peak to peak, and the purpose of proposing a DAC is being able to generate multiple frequencies, even extremely low frequencies (under 1 Hz). For a clearer insight it's for a heater pilot wire for which you can find the needed waveforms at: goo.gl/CnnD1k
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Extra small RF PCB antenna - GND plane
@Mikey Thanks for your help, I considered already all these points and spent enough time on the problem to know for sure that beside the battery nearby the problem is, the design of ground plane and its size/antenna combination
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Extra small RF PCB antenna - GND plane
@Mikey I don't know if the reception antenna is isotropic or not, but the antenna and PCB are rotated around all axes and only the max value kept
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Extra small RF PCB antenna - GND plane
@Mikey, I already removed the battery, re-tuned the antenna the radiated power increased to -8 dBm, but still not enough (measured in Anechoic chamber at 3m from antenna and with standard EMC lab amplification)
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Extra small RF PCB antenna - GND plane
@Mikey, The PCB works in TX mode only, for the measurments: the radio chip outputs 13 dBm however the PCB only radiate around -14 dBm
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Extra small RF PCB antenna - GND plane
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Extra small RF PCB antenna - GND plane
I already tuned the antenna, the radio chip outputs 13 dBm however it only radiate around -14 dBm. There is also a coin cell battery placed under the PCB which reduces the performances further. Other PCBs with bigger ground plane can radiate 5 dBm
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Extra small RF PCB antenna - GND plane
all design instructions are followed and the antenna was matched. However I still get poor RF performance compared to bigger PCBs
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Assemble a 9 * 9 * 0.05 mm steel foil and castellation PCB using standard pick and place
Since I gave up on the first idea, I now think about using a constellation PCB is that easier to achieve ?