JPS6168684U - - Google Patents

Description

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は本考案の一実施例に係るゼロクロス検
出回路の回路図、第２図ａは従来例における高１
次電圧時の動作タイミングを模式的に示すタイミ
ングチヤート、第２図ｂは従来例における低１次
電圧時の動作タイミングを模式的に示すタイミン
グチヤート、第２図ｃは前記一実施例の高１次電
圧時の動作タイミングを模式的に示すタイミング
チヤート、第２図ｄは前記一実施例の低１次電圧
時の動作タイミングを模式的に示すタイミングチ
ヤート、第３図、第４図はそれぞれ異なる従来例
の回路図である。 １……比較器、２……入力トランス、３……抵
抗回路、４……整流回路、５……平滑回路、６…
…分圧回路。 Fig. 1 is a circuit diagram of a zero-cross detection circuit according to an embodiment of the present invention, and Fig. 2a is a circuit diagram of a zero-cross detection circuit according to an embodiment of the present invention.
FIG. 2b is a timing chart schematically showing the operation timing at low primary voltage in the conventional example, and FIG. 2c is a timing chart schematically showing the operation timing at low primary voltage in the above example. FIG. 2d is a timing chart schematically showing the operation timing at low primary voltage of the above embodiment; FIGS. 3 and 4 are different from each other. FIG. 2 is a circuit diagram of a conventional example. 1... Comparator, 2... Input transformer, 3... Resistance circuit, 4... Rectifier circuit, 5... Smoothing circuit, 6...
...Voltage divider circuit.

Claims (1)

【実用新案登録請求の範囲】[Scope of utility model registration request] 比較器を備え、該比較器の正相入力端にトラン
スの２次電圧を印加する一方、該比較器の負相入
力端に前記２次電圧を整流平滑した非安定化電圧
を印加し、前記２次電圧が前記非安定化電圧と等
値になるごとに信号値が高低に切換えられるゼロ
クロス信号を上記比較器が出力するように構成し
たゼロクロス検出回路。 A comparator is provided, a secondary voltage of the transformer is applied to the positive phase input terminal of the comparator, and an unstabilized voltage obtained by rectifying and smoothing the secondary voltage is applied to the negative phase input terminal of the comparator, and the A zero-cross detection circuit configured such that the comparator outputs a zero-cross signal whose signal value is switched high or low each time the secondary voltage becomes equal to the unregulated voltage.