0
  • 聊天消息
  • 系统消息
  • 评论与回复
登录后你可以
  • 下载海量资料
  • 学习在线课程
  • 观看技术视频
  • 写文章/发帖/加入社区
会员中心
创作中心

完善资料让更多小伙伴认识你,还能领取20积分哦,立即完善>

3天内不再提示

信号寻迹器/信号发生器(英文),Pulse-Generator & Signal-Tracer

454398 2018-09-20 19:21 次阅读

信号寻迹器/信号发生器(英文),Pulse-Generator & Signal-Tracer

关键字:信号寻迹器/信号发生器

Dual-purpose test-instrument
Very simple circuitry, 1.5V Battery-operated
Circuit diagram

Parts:
R1 1M 1/4W Resistor
R2,R4 2K7 1/4W Resistors
R3 150K 1/4W Resistor
C1 2n2 630V Ceramic or Polyester Capacitor (See Notes)
C2,C3 4n7 63V Ceramic or Polyester Capacitors
D1 1N4148 75V 150mA Diode
Q1 BC547 45V 100mA NPN Transistor
Q2 BC557 45V 100mA PNP Transistor
SW1 SPST miniature Slider Switch (See Notes)
J1 Stereo switched 3mm. Jack socket (See Notes)
Probe Metal Probe 3 to 5 cm. long
Clip Miniature Crocodile Clip
B1 1.5V Battery (AA or AAA cell etc.)
Device purpose:
This simple circuit generates narrow pulses at about 700-800Hz frequency. The pulses, containing harmonics up to the MHz region, can be injected into audio or radio-frequency stages of amplifiers, receivers and the like for testing purposes. A high-pitched tone can be heard from the speaker of the device under test when all is working properly. The clip must be connected to the ground of the device under test, touching with the probe the different stages of the circuit, starting from the last stage and going up towards the first. When the tone is no longer heard, the defective stage has been found.
Connecting an earclip or headphone to J1, the circuit will automatically change into a two-stage amplifier and any audio signal coming from the device under test and picked-up by the probe will be heard through the headphones. The testing of a circuit should be made in the reverse manner, i.e. starting from the first stage and going down until the last stage. When nothing is heard, the defective stage has been found.
Circuit operation:
Q1 & Q2 form a complementary astable multivibrator, whose operating frequency is set mainly by R3, C2 & C3 values. Output pulses are taken at Q2 Collector and applied to the probe by means of decoupling capacitor C1. D1 provides a symmetrical shape for the output waveform.
If an earclip or headphone jack is plugged into J1, the connection from Q2 Collector and C1-C2 is broken by the switch incorporated into J1: in this case the circuit becomes a two-stage amplifier.
Notes:
If you intend to use the circuit to test valve operated devices C1 must be a 630V type. Working with low voltage supply transistor devices the voltage of C1 can be lowered to 63 or 100V.
If instead of a short probe, you intend to connect the circuit to the device under test by means of a piece of wire longer than a few centimeters, a small ceramic capacitor (470 to 1000pF) should be added in parallel to D1 to prevent unwanted RF oscillation.
Current drawing when in Pulse-Generator mode is about 60µA & 1.2mA when in Signal-Tracer mode operation. Therefore SW1 can be omitted, provided that the earclip or headphones are unplugged when the circuit is unused.
J1 is a stereo switched jack socket wired to obtain a series connection of the two earpieces forming a stereo headphone. In this manner the circuit is loaded with a higher impedance and sensitivity will be improved.
Therefore, the higher the load impedance the more sensitive the Signal-Tracer. In any case, common 32 Ohm impedance mini-headphones suitable for walkman sets will work fine.
A crystal (high impedance) earpiece is a good solution, provided you substitute J1 with a mono switched jack socket.
The entire circuit can be easily fitted into a pen-like enclosure, with the probe protruding like a nib.
Author: RED Free Circuit Designs
声明:本文内容及配图由入驻作者撰写或者入驻合作网站授权转载。文章观点仅代表作者本人,不代表电子发烧友网立场。文章及其配图仅供工程师学习之用,如有内容侵权或者其他违规问题,请联系本站处理。 举报投诉
收藏 人收藏

    评论

    相关推荐

    数字信号发生器怎么调有效值

    数字信号发生器(Digital Signal Generator,简称DSG)是一种用于产生各种数字信号的设备,广泛应用于通信、电子测量、自
    的头像 发表于 06-03 14:14 1210次阅读

    数字信号发生器能够提供哪些波形信号

    数字信号发生器(Digital Signal Generator,简称DSG)是一种能够产生各种波形信号的电子设备。它广泛应用于通信、电子测
    的头像 发表于 06-03 14:12 967次阅读

    数字序列信号发生器如何测量

    数字序列信号发生器(Digital Sequence Signal Generator,简称DSSG)是一种用于生成数字序列信号的设备。它广
    的头像 发表于 06-03 14:04 367次阅读

    信号发生器频率怎么调

    信号发生器是一种电子设备,用于产生具有特定频率、幅度和波形的电信号。这些信号可以用于测试和校准各种电子设备,如放大器、滤波、振荡
    的头像 发表于 06-03 11:06 1486次阅读

    信号发生器的sync什么意思

    信号发生器是一种电子设备,用于产生具有特定频率、幅度和波形的电信号。这些信号可以用于测试和测量电子设备的性能,或者作为其他电子系统的输入信号
    的头像 发表于 06-03 10:59 2781次阅读

    信号发生器的使用方法 信号发生器的幅值是有效值吗

    信号发生器是一种电子设备,用于生成具有特定特性的电信号,如正弦波、方波、锯齿波等。信号发生器广泛应用于测试和测量领域,如电子电路设计、通信系
    的头像 发表于 06-03 10:56 2489次阅读

    任意波形发生器和矢量信号发生器有什么区别

    在电子测试与测量领域,任意波形发生器(Arbitrary Waveform Generator,简称AWG)和矢量信号发生器是两种常见的信号
    的头像 发表于 05-30 16:02 2417次阅读

    脉冲发生器的分类 脉冲发生器的怎么设置参数

    脉冲发生器Pulse Generator)是一种电子仪器,用于生成特定形状和特征的脉冲信号。它通常用于电子测试、实验室研究以及其他需要控制脉冲信号
    的头像 发表于 04-27 10:39 2058次阅读

    信号发生器怎么输出调制信号信号发生器的功能和使用方法

    信号发生器是一种用于产生不同类型信号的电子设备,常被用于测试、校准和排除电子设备。调制信号是一种将基带信号与载波
    的头像 发表于 02-23 16:38 2899次阅读

    信号发生器怎么产生差分信号

    信号发生器Signal Generator)是一种产生特定类型信号的仪器,常用于电子设备的测试、测量和调试。差分
    的头像 发表于 02-23 16:35 3048次阅读

    信号发生器是干什么用的 信号发生器和示波器怎么连接

    信号发生器是一种用于产生各种电信号的设备,它在电子设备测试、电路调试、教学实验等领域得到广泛应用。信号发生器可以产生不同频率、幅度、波形和相
    的头像 发表于 01-30 10:08 2801次阅读

    信号发生器是干什么用的 信号发生器的使用方法

    信号发生器是一种电子测试仪器,用于产生各种类型的电信号。它可以在实验室、工厂和其他领域提供标准化的、可重复的信号,用于测试和验证其他电子设备的性能。
    的头像 发表于 01-19 14:51 2875次阅读

    信号发生器如何发出双脉冲?

    信号发生器如何发出双脉冲? 信号发生器是一种用于产生各种信号波形的仪器。双脉冲信号是一种特殊的
    的头像 发表于 12-21 15:03 2004次阅读

    信号发生器怎么输出调制信号 信号发生器输出信号衰减如何调整?

    信号发生器怎么输出调制信号 信号发生器输出信号衰减如何调整?
    的头像 发表于 12-21 14:56 5688次阅读

    信号发生器在射频信号处理中的应用与技巧

    信号发生器在射频信号处理中的应用与技巧 信号发生器在射频信号处理中是一种常用的测试仪器,广泛应用
    的头像 发表于 12-21 14:56 684次阅读