Deprecated: Method ReflectionProperty::setAccessible() is deprecated since 8.5, as it has no effect since PHP 8.1 in /var/www/html/plugins/system/falangdriver/falangdriver.php on line 534

Deprecated: Using null as the key parameter for array_key_exists() is deprecated, use an empty string instead in /var/www/html/plugins/system/t4/src/t4/MVC/Router/T4.php on line 388
在测量离板信号线的传导骚扰时，发现在两个特定频点（一个是 659K 另一个是 1.977K）上由两个很大的噪声信号。初步分析是由于板上的开关电源芯片引起的，如何 - Bluetooth forum - bluetooth蓝牙技术
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Deprecated: Using null as the key parameter for array_key_exists() is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/cbPluginHandler.php on line 323

Deprecated: Using null as the key parameter for array_key_exists() is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/cbPluginHandler.php on line 323

Deprecated: Using null as the key parameter for array_key_exists() is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/cbPluginHandler.php on line 323

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在测量离板信号线的传导骚扰时，发现在两个特定频点（一个是 659K 另一个是 1.977K）上由两个很大的噪声信号。初步分析是由于板上的开关电源芯片引起的，如何


Deprecated: Using null as the key parameter for array_key_exists() is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/cbPluginHandler.php on line 323

Deprecated: Using null as the key parameter for array_key_exists() is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/cbPluginHandler.php on line 323
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25 Oct 2020 12:54 #139 by btt
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Q:在测量离板信号线的传导骚扰时，发现在两个特定频点（一个是 659K 另一个是 1.977K）上由两个很大的噪声信号。初步分析是由于板上的开关电源芯片引起的，如何使用示波器测量这样的噪声信号？
A:示波器可以测试噪声信号有几个考虑的因素： ① 被测信号的幅度，是否为小信号， 示波器配合探头可以测试 uA 级的信号 ② 被测信号的频率。 ③ 探头的连接方式不当会产生噪声，影响测试结果。

Deprecated: Using null as an array offset is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/LegacyFoundationFunctions.php on line 234

Deprecated: Using null as an array offset is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/LegacyFoundationFunctions.php on line 237

Deprecated: Using null as an array offset is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/LegacyFoundationFunctions.php on line 239

Deprecated: Using null as an array offset is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/LegacyFoundationFunctions.php on line 189

Deprecated: Using null as an array offset is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/LegacyFoundationFunctions.php on line 237

Deprecated: Using null as an array offset is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/LegacyFoundationFunctions.php on line 239

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Deprecated: Using null as the key parameter for array_key_exists() is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/cbPluginHandler.php on line 323

Deprecated: Using null as the key parameter for array_key_exists() is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/cbPluginHandler.php on line 323

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Deprecated: Using null as an array offset is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/LegacyFoundationFunctions.php on line 189

Deprecated: Using null as an array offset is deprecated, use an empty string instead in /var/www/html/libraries/CBLib/CB/Legacy/LegacyFoundationFunctions.php on line 237

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Deprecated: Method ReflectionProperty::setAccessible() is deprecated since 8.5, as it has no effect since PHP 8.1 in /var/www/html/plugins/system/falangdriver/falangdriver.php on line 100

Deprecated: Method ReflectionProperty::setAccessible() is deprecated since 8.5, as it has no effect since PHP 8.1 in /var/www/html/plugins/system/falangdriver/falangdriver.php on line 100
mysqli object is already closed (500 Whoops, looks like something went wrong.)

Error

HTTP 500 Whoops, looks like something went wrong.

mysqli object is already closed

Exception

Error

in /var/www/html/libraries/vendor/joomla/database/src/Mysqli/MysqliDriver.php (line 318)
  1. */
  2. public function disconnect()
  3. {
  4. // Close the connection.
  5. if (\is_callable([$this->connection, 'close'])) {
  6. $this->connection->close();
  7. }
  9. parent::disconnect();
  10. }
in /var/www/html/libraries/vendor/joomla/database/src/Mysqli/MysqliDriver.php -> close (line 318)
  1. */
  2. public function disconnect()
  3. {
  4. // Close the connection.
  5. if (\is_callable([$this->connection, 'close'])) {
  6. $this->connection->close();
  7. }
  9. parent::disconnect();
  10. }
in /var/www/html/libraries/vendor/joomla/database/src/DatabaseDriver.php -> disconnect (line 496)
  1. *
  2. * @since 2.0.0
  3. */
  4. public function __destruct()
  5. {
  6. $this->disconnect();
  7. }
  9. /**
  10. * Alter database's character set.
  11. *
DatabaseDriver->__destruct()

Stack Trace

Error 
Error:
mysqli object is already closed

  at /var/www/html/libraries/vendor/joomla/database/src/Mysqli/MysqliDriver.php:318
  at mysqli->close()
     (/var/www/html/libraries/vendor/joomla/database/src/Mysqli/MysqliDriver.php:318)
  at Joomla\Database\Mysqli\MysqliDriver->disconnect()
     (/var/www/html/libraries/vendor/joomla/database/src/DatabaseDriver.php:496)
  at Joomla\Database\DatabaseDriver->__destruct()

Deprecated: Method ReflectionProperty::setAccessible() is deprecated since 8.5, as it has no effect since PHP 8.1 in /var/www/html/plugins/system/falangdriver/falangdriver.php on line 100

Deprecated: Method ReflectionProperty::setAccessible() is deprecated since 8.5, as it has no effect since PHP 8.1 in /var/www/html/plugins/system/falangdriver/falangdriver.php on line 100