大功率灯珠 / 背光维修
High-power bead / backlight repair
核心特点
Core features
- 两档电压：高压 0~300V / 低压 0~140V 拨动切换，兼容各类灯板
- 九档恒流：1 / 5 / 30 / 70 / 100 / 150 / 200 / 250 / 300mA 按键设定
- 缓升输出：软硬件双重缓输出，灯光渐亮，保护灯珠不被烧坏
- 双变压器冷热隔离：安全不触电，仍严禁同时触碰输出两极
- 自动待机：空载 20 秒进入待机显示「---」，短接表笔 1 秒即可唤醒
- 免拆屏测试：不拆屏即可点亮电视背光判定灯条好坏
- Two voltage ranges: HV 0~300V / LV 0~140V by toggle switch
- Nine current steps: 1 / 5 / 30 / 70 / 100 / 150 / 200 / 250 / 300mA
- Soft ramp output: hardware plus firmware ramp protects the beads
- Dual-transformer isolation for safety; never touch both poles
- Auto standby after 20s idle, shows "---"; short the probes 1s to wake
- No panel teardown needed to light and judge TV backlight strips
产品多视角
Product views
典型应用
Typical uses
- 大功率灯珠、灯板点亮与好坏判定
- 液晶电视背光灯条免拆屏测试与电压对比
- 整条长灯条点亮，观察亮度是否均匀
- 配合万用表核对读数，排查开路、短路与漏电
- Light and judge high-power beads and boards
- TV backlight strip testing without removing the panel
- Light full-length strips to check brightness uniformity
- Cross-check with a multimeter for open, short or leakage faults
电气参数（说明书摘录）
Electrical specs (from manual)
| 型号Model | CF300 |
|---|---|
| 供电Supply | AC 85~265V |
| 输出电压Output voltage | 高压 0~300V / 低压 0~140VHV 0~300V / LV 0~140V |
| 输出电流Output current | 0~300mA，9 档恒流 0~300mA in 9 constant-current steps |
| 显示Display | 输出电压 + 输出电流Output voltage + current |
| 隔离Isolation | 双变压器冷热隔离Dual-transformer isolation |
| 保护Protection | 缓升输出、小负载自动限流、20 秒自动待机 Soft ramp, foldback on small loads, 20s auto standby |
负载电压低于 50V 且电流设定超过 200mA 时，仪器会自动限流至 200mA 以保护灯珠。电流设定大于 30mA 时，前 3 秒会限制输出，之后恢复大电流。
With loads under 50V and a setpoint above 200mA the unit limits output to 200mA to protect the beads. Above 30mA, output is limited for the first 3 seconds.
使用要点
How it works
- 接入 AC85~265V，等待电压表显示高压 270V 或低压 130V 后插上红黑表笔
- 红黑表笔分别接触 LED 光源正负极，光源在 1~2 秒内由微亮缓升至稳定高亮
- 短按按键设定小电流：1 / 5 / 30 / 70 / 100mA；长按设定大电流：150 / 200 / 250 / 300mA
- 未显示电流时，短按第一下会显示当前电流设定值
- 空载 20 秒后进入待机显示「---」；短接表笔 1 秒或短按按键即可恢复输出
- 确需长时间输出时，长按按键 8 秒以上，长鸣一声后可关闭自动待机
- Connect AC85~265V and wait until the meter shows 270V (HV) or 130V (LV), then plug in the probes
- Touch the probes to the LED terminals; brightness ramps up over 1~2 seconds
- Short press sets low currents (1 / 5 / 30 / 70 / 100mA); long press sets high currents (150 / 200 / 250 / 300mA)
- When no current is shown, the first short press displays the present setpoint
- After 20s idle it shows "---"; short the probes for 1s or press the key to resume
- For continuous output, hold the key over 8 seconds until a long beep disables auto standby
免拆屏测试背光
Backlight test without teardown
- 拔开恒流板与灯条之间的接口插座
- 将红黑表笔对应插入 LED 灯条接口的正负极
- 打开电视机电源，使除恒流板以外的部分正常上电
- 灯条、屏、主板与逻辑板都正常时可看到画面，亮度略低于原机属正常
- 同一台电视每组灯条电压应相同，误差超过 3V 说明该灯条可能有问题
- Unplug the connector between the constant-current board and the strips
- Insert the red/black probes into the strip connector polarity
- Power on the TV so everything except the CC board runs normally
- A normal picture appears if strips, panel, mainboard and T-con are fine; slightly lower brightness is expected
- Strip voltages on one TV should match; a gap over 3V points to a faulty strip
读数判读技巧
Reading the results
- 显示电压等于开路电压：被测灯条可能接反或存在开路故障
- 显示电压为 000V：被测灯条或灯珠短路
- 测试两个无电气连接的对象时电压明显低于开路电压：两者之间存在漏电
- Reading equals open-circuit voltage: reversed polarity or an open circuit
- Reading is 000V: the strip or bead is shorted
- Voltage clearly below open-circuit across unconnected parts: leakage between them
常见问题与安全
FAQ and safety
- 待机时触摸表笔安全吗？空载约 20 秒进入待机后，输出被限制到极低，可用手触摸表笔（如图示）；测试输出中请勿同时接触两端
- 不测试时可以不断电吗？待机时输出在安全范围内，但仍建议拔掉电源
- 3V 灯珠为何测不到 3V？按 U=IR，低电流时电压达不到 3V，电流上升后即可达到甚至更高，属正常现象
- 反接短时间一般不会烧整串灯珠；质量较差的单颗小功率灯珠仍可能被反向击穿，不建议单颗反接
- 警告：测试时请勿同时接触表笔两端；长期不用请断开电源
- Safe to touch probes in standby? After ~20s idle, output drops to a very low level so you can touch the probes (as shown); do not touch both ends while testing
- Can it stay powered when idle? Standby output stays in a safe range, but unplugging is still recommended
- Why does a 3V bead not read 3V? By U=IR the voltage stays low at small currents and rises with current — this is normal
- Brief reverse hook-up rarely damages a string; weak single low-power beads may still break down, so avoid reversing them
- Warning: never touch both probes while testing; unplug when unused for long periods
整箱装运
Bulk packing
| 30 台 / 箱30 pcs / carton | 45.5 × 34 × 41 cm |
|---|---|
| 50 台 / 箱50 pcs / carton | 59 × 45 × 41 cm |
以上为常规装箱方案，实际重量与唛头按订单确认。
Standard carton options; actual weight and shipping marks are confirmed per order.
相关型号
Related models
CF300 是系列中电流最大的一款；需要漏电检测与双表头选 CB250，便携缓升选 CX300，经典入门选 CA250。
CF300 offers the highest current in the line; pick CB250 for leakage detection with dual meters, CX300 for a portable soft-ramp unit, CA250 as the classic entry model.