------=_20030310123809_64756 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit RADAR Engineering Team said: > I was under the impression that the TIPs already had the diode from CE. > Even though, I have tried the diodes and it did not seem to help (I will > add the resistors and try it again though, Thanks for the time and > assistance). Yes they do have the diodes and pinch-off resistors. See the attached internal schematic of the TIP12x series darlingtons. Others in that series are quite similar. > Bob, I did not use your "cool" schematic because I was simulating it in > PSPICE and that is just how it ended up looking. I do thank you for the > help (and the great web page). I just assumed you got it from someone elses website and wondered why they decided to redraw it etc. > When I simulate I do get a mean transient response. There is a terrible > short when the actual switching takes place. I tried a couple > approaches to get rid of some of the spike with little success. I am When you say switching do you mean toggling from A-on to B-on? You can't do that without adding a small delay. Turn-off takes longer than turn-on, so if you toggle the two sides with no delay you'll get that. > haveing a hard time seeing the difference from the PSPICE schematic and > your web picture. Please help! You should have a big capacitor on the power input because otherwise you get voltage spikes each time you turn off, as the motor dumps its stored energy. Batteries are not capacitors. Especially at the end of a long wire. On a related note, that bridge, even with TIP14x transistors, is only good for 10 amps, or 40 volts, or 200 watts, whichever comes first. The losses of darlingtons is fairly high. It also will not run at 20KHz. Even if you add extra pinch-off resistors you can't get to the inner base, so the turn-off speed is limited. I've used it with TIP14x parts at 18 volts, 10 amps with 300Hz PWM and it runs quite cool and does not fail. It is meant to be a low parts-count bridge and there's no way you can make it do what you want. You should look into MOSFET high-side driver chips if you want a simple circuit that can make a bridge that does what you want. I like the IR2112 but there's also a nice LT chip. Cheerful regards, Bob Blick -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details. ------=_20030310123809_64756 Content-Type: image/gif; name="tip12x.gif" Content-Disposition: attachment; filename="tip12x.gif" Content-Transfer-Encoding: base64 R0lGODdhAAQAA/cAAAAAAAEBBhEPDwoRDhcTDQQFFhIOFg4SGhYVGSMcGB8hGyonFwcJJxENJw0R KhUWKAgLNREONAwTNhYZNiIcKR0iNCcmKDUnJy40KTgyJyYoNTMoNy0yOjY2NkY2Lz5BO1FMOWFX O2hmOQkNRQ0URhUZRwkNWA4YVRcaVxslRRolWCYpRTMqQy00SjY4SCQoWSo1VjM5VgoPaAwVaBga ZAkPcQ0TdxQbdyAecxsnaSQrajAraCg1aTQ7aSUpeSo1dzU7eEY5SDpDTzZGb0hIRVlMRkhQS1hZ R0ZJWExVWFdXWGRUTFpmWmVlS2lxSWdpWnRmVWdyWXd3WkRKZVZNY0hSZ1dZZkVMdUhWeFZbd2hV aVlobmppaXNlYWx4aHp5aWhodXNhfGt1dnd6eod6V4d7a3qIWHuGcoqNVYWHa5aIaYiTaYeLdpWP eIyWeJ2UdaOddZWifKimfBMZixwljjA1iBwkoDA6oEI7kDRKij1hlzJArUZTjmNfjFFrk2l3kUdd qVRwpWp5pYx8gnmIiHyUjWiFnHWJl3qYmF2EoGmKpnWLpHqUpm6Ps3SLtHqWs3eirXqgxISNh4qY h5eahoSMmYibl6Odh4ijiZijh5qwjIqkmJmllpuxmKOoi6i3jLK0jqOqlqe1lrW5l4SYp4unqJao p5mzqYyptJens5e2s6mmo6e5pbO7o6CtvaW6tcG6ks+9oLbFlprBuqfCprjHpbrUq6nGt7TJuLvV t87Jmdrine7incfKpdXIpsnVptbapcTNutTPs8rYttbctOXZqtPms+jnqej1qObotun1uZCpxaW3 xpyz5LC64qnIx7XLx7zVxarH3rTJ1rnV17XL8M/byubawcziy9noyMvyyNbyy8vl19rr18/y1tr0 2Ofnx+r2yOTs1+f21tDY7cvl69vq68T27t327eXp6+b27v////////////////////////////// /////////////////////////////////////////////////////ywAAAAA2wB5AAcI/gDVCRTI bKDBgwgTKlzIsKHDhxAjSpxIsaLFixgzatzIsaPHjyAd9gpJsqTJkxfRoVzJsqXLlzBjypxJs6bN mzgzlgig7kWALwILBKgVoKjRDkaLsgIntGiBceoKEBEYDIEygRYsQBXYYUzDIwUKHDFIxACCUep6 fRooqpa6ZLV6yWqrLlytcAPDbVUHbq84awuVJcOb8+aEALgO81SnlEHTAAU0JC3AKlfSokQDhFJH KIAodZyKehBILAADhpcLqLN2OUFRcAIhM748zmjsogJd4J59WbayyQh/JQURVLXAFQWKGEQKebO6 IB4yePCQbGCrNMQGUvI0cFSrmSsC/rwKHwDBbHK30U8JcMqgcAtBPdsuFMBSVNvqhslWmE22NaHR xABZNLQklV04shWFSCmqvMJbML7Y1h9m6iySBwwBHKDDEAlCdkhRShwki1NFPTDbQE4NhACJQ/Fm FFS17SdKUWeokwmNMjkQwDAVBPBAAKPsdqI6SASwAAUgTKUfBbVIopRRGnRGCGtGDRObcQo5dYYt 0ExT1C0CmZJHUVJM4kaHuAhUTjdGETEjbpn5OBBRGpjzWwHCLYbgae4F0IE6eRqzWyhGGaPOneZw ZtpsgFURQBLqBLnbm6cpJolMhxlzWGj4DSlgUupYltQmtkAm1BEBSDIJZJ2dVhuW/wn5MRkuRSWK YmoudghZC0Zl02MSRQGWVgAuXDkiBwwJV6w6h72ZqFBRBDAWhlMIlA0u0sRozDBIVaHOj0I9AZpT CBblVUyHZSNZLn90utsWAXCiEmmQIQJvAKU+YIpRkzQlAG76wZqQMadgGMATwQpkTRxFEYLNvqoV lYIKJeQx249JlRpAJz8CpQ5RyIID2Yx/LgRMAFOpI2CBPP2G72sCpglEUael9ozLM6rmiZEBfBIA AQGIIdOPwUjGyn2LDSlGAFKI0ssx4fzGJ2aySVBUtJe1guBTC+13RgBK/NiEOtAk5dbWjBpEY1Er BrAqcB8HIIQ6rwq6WGkCE4XEbf6iqvM2vwJC6odQBZSrQgpFKfMmCEX9MiPjCwRgRgDnwnRYODu5 ZfetAq2X1APCmTjbjKfZHXkBKmVhmsv8ItTbLXn29h3aqWX25tLlZcgHhwHgRVQFdckm1AJfBzDB QcIVkMaKBdAaQIyTcapMN6s+tZtPtWBs1AerMl7UqpXDJI5A0QzUTfkCoWPKQKqUcsoplkCjzim5 CKTKH90coopAt+TxxxDrE8gQAqGOH6jgBSVQgfwOMgyrQaY9FWpK8yBQgGwE5TSPKQouhGK3YTxm ICoIwNF6EYC9MUY1GuvUQOxmFGrMphVFkV+e1ME7o0RsMT5Bg1Jw0QnIrEoDiP4rQA8hVZgiFpEU jChIQgj0ijQJZBioUAcrpsE+UgjkEAVgwB9YQUA+1EEgysjBIVBAh4GQYAS10OIiCgAEVjDAikYE CXpkMsc42vGOeMyjHvfIxz768Y+ADKQgB2kQWxHykBCpIyIXychGOvKRkIykJCcZyWHs5WMnaQZF FEnJPaZDIaXBQi8s8CexdNIilyQJJ43YFDYgZAsmekF4WJGMpJ0yIk1gwDikcIZa/IFPtxTIzqxx CiwRJgVCSwdRoBIAYQVzIEIRnUHCUYBcbKEAE2BAOBjwmWdOgAsHsUB5xjEBQsTNW4wZ3zODooFc 0MCEednbN4IBgxiooxPhO//lBDwmEAQRRQwlsADrGFBLQz6zALSYZgEsEI5wLAsKxvnFpRaiSUcK x3E8gR4uBPULXODiFNCYAPDWGRQrDQQJD8gEA36TDNUFQAPjqMAWSLqTADDiiRMwKS7gKBAUkHQg JehAMgowNx6kqASgY8QiliGLAkjjpwjRAVQbogyhAPMUyDoUMNXBAEe4JAIQYIBYGeAgQYyVAcfj 6gMm0IAHvEAgFNAABTrQAaj8gQh4xatAKiGFJ5zhC660kRvSEAc3uAU0oniAJjohEFuwohOtaMVh lVGLXCgjO+hJJSTn1c8h4AQCJ7GVrbpBjtFCwxrRiIatmjgBUzhIHc8wRSmBGEGKRQiEEYZA4h9S IRASkCSLZxUIDc7qU646oAAPeMAK1NGDB2igAxpIGRia8IQncMENAgnFJDxBCU4QRrK1aIVJiZEM XXTAUDYBbRxLYBEg/NYknFUHOqaBC2rM6xW3UMUtqKiOUpjiEBpYREUdIQhB+EEQAgEEH7xYB0AI ZAQM/gGIOoEDCRYsKMFgQoULGTYsuMKhwiERKRYsUBFjxoTjrGhUV8JjQwYhB/YC0QEEiCZHjjQ5 E+XLkzNn3LiZ5KmmG0+ZZH3yxGnULlmiAgQoAKxWrWS9gBUjRgxYOGUJ+ZBseNFq1oXHlHgkodWg iax/zpy6ZQotq1KWSpX682fTHz+M3sr904PPED5Ahgx5oaJoABUlCENgYFjCYQYdC1YFaxAryZQg jjg5IuXJmjRs4rjJRCnTJ1GhRCU13StXMWXDfk0q+ivbuHEVITy2re4PsdsCxzGA1jBcld0MR1gd F8AsLlWpSqV6RcrSIlJ/BFH/wwd7njx8fuTQgSIH/mEGRQtAMG+eQXr1tQsW3z3bapZfw9WhiDiG Pv3jw8Px0OCQjvwKGsmqAkKhDySHpjCojvzgIykA+sLhwqE56CuggAeSEYhAj4wJoIL8Xoioq4J+ yC8yj2qJkL8zADRohqzCCaAUGB7gMCQXAjhRRIfGQcIgHrNSpigDBkoxIzaQ048xhuwwyD2Sjqul gAlw1MgoXAT8KKImB2pQK2U2oaUALdVBsiIEynQQjBcLOiGr4yYIwEV1OnRICXGIQlMhVkga0SH8 CtIBrGTYOCOAYATis6FiAphoS0ncJIiEBz1KJoBszsAKzIgCWCCAP7YcyD6HxDDIEbCISSGFAIxZ /rSiI8JR0pRRx2GjQijJMS6wQ7AMgJtRByLUIUnpq4WWcQrwU507KCLSKFSEDUdQhiwsaA+txsnF nIGKqSgAZoVVRwUfKSzoFbB6CUwjYAJIcNxqFwpwuBVdvVKdICxVZ9eBAhhmXIFKbahEgoTUKhuC WqHI3VoCVsdYhm4wCBytApikgAA+WaOAODIJbKhPdPnlF1l+QUaWADYMeGCGvBQIiMesMOpIgcKx YCqFPgnAzHEjXuhaguDMigEEAnDgFmgKiAaXB4p6JRqzTsmFlVxKQYTnh1GYxqFzDX4sgE0CAOEL NAJww+yiMslEl1Bk8UUXXUSRIwCHA/5ZoaAH/mLPOBIMGYjAdAKwZiFx7mU5ojYHBbsoS9ShkumM H/DmlXGoAccaaKx5xbX5xh0H74T0Fohv2zpk1F/Pxy3XIcUJIlbbHPyoWR1iUFfHXUUDniTXgkrH SAOE1JkNgv8saqioTwLOwUdCULUqmZUFqnj4yH4vaEVxhXW+odHViRIjVgY/kxN1cGGRoALSYSiA TgKwIBxhaWBo13BCzyoAQs8t4AuBytmbIcgoit2ExbvuGYReGSEEDwSyCcep4wGF4NKi+iWSAPRi VLBjiOu+RJIhXOQPAdiGOoyBpusR5BeBOZutMtE7rViiTuGoFQQleLqKHCIAIrhRflq2EHkJ/8QH JMGCn6zRipyVqkMnLMiMaDYq7lnLIBPTCCKwEg5RCCRrgStAtyjCiaKUjz493IivChLEkPQAYOoI R8LUcQVYCQR8CwkHNF5QgH3txoASg1JIAnDFgayARVZ6I0VI4YCiSO82X1mIKHqRCRBwQhbi0mBG euACgRADYDMapBL7FIA4CIgSDpEiQTjpkHQNJBW/UYfwzuQRDRxoOPBKCIZUGJmDZWRGtkif8CJz p4iEowAOyM/91KhC8sRPHaUMiSJbmZBk1OJVCcFCGm+jrIbYiwgFSaBHcFENgiyCdnbSiCbpA8aE jEeFwlSHMny5G0YFYAIZS8gQtAeWUASgnf4FcVpRcjaqJCqkFqOIikGASR9C9E8hTAzMMwYSR7AQ 8J20SGFCsmAUDCEAoZIJACMacgwVWuBhpFNIAXhQgHzeziPheEABKjjPwGRhVIJspkECg5U6EcQc mqNFiELyoQC0VCHG1NhAmEefOqFDiQwYxif4ZFEMHeCOGOkFAZRZvSZuSabvdB8mFpULgBoPI09Q B1GwEJESCDUyZhyO9YJalKqEwwgGQYc6rFELNnqkoo5hiAUyACoFUGZvXLRNVoM6DD9gxa4KUUYH sASCAMzQIdkohSk6cQSzMIOo+mHrOS3BIj4cziDH0Egr3DAOJ4zPIXWogw4KoIIc3ICLVf7ViEzR VxBVpkIgvRCHQpIBkYzg0xXjhGlBOlXNzRpkJCowXgF0k5B+VgQGARgAShMiFt8Nh7AKsdQwCJcQ YFjytyQJXVF3U1CR0g+L1CyIMrpbkVbpFSM2MIhsM4JZChLEFAFAAQp0QAP/0gAFNBgBBJCUjGyG NyTEvBAADZKNDYVDNsrgw3MJ0ov1YaQE1M3bfLfkyU/IoidmuN2ManEMZRjDGBigkzLgE9WC1FaB D1sG4ArSgxfwAQ+qrYMPUIADHwB4C9hz8UJ0kM+IyLcgzhhOGAbiByfzwA9DSAFKA5ACEkiABIYs igMSox4GYAjMYS5KSMKRx4HgQVgFgGMCGcrQZgRQeIkg6EUxklEMShRlGOEQRjLAUbEHWWocDjCy Q2IkLFkWhBMjRtKcboFgjYzjiZktyIWzwjdVlOIUhpDLBBBpEGX9gAc8yHBRGFCCxEgAAqhWT5hp OeiGyMAgYiT+CEDUCRxIsGDBFQYHnirAoABDhxALBGBQsFaBhBgHBsjIUaAlgzk6isSojCJGHaGU gVOXbKC1ceqUbSGYa4KKkQQdOMBpsIZBCDx5Tggq8tdFogE2ElU3jpBBGktHhjOZ0A8JCFghMGgY 8VBBUbiITqBKVIZBslETIkyb0OjSAH8CxCGqjJNBFGw5jjualyCrpQ8CNAm31GxBtH0F4k080BZf nrfUMQpggKiou4wNTs0skFU2ohKSBtBQ9izn0wSTPSZqjPIonpMMSkM9EHHeXkuhnaoSYLVIwwRt 085rzPdAiLgzMgiAQGqo4dALtmL76FABYjxtGGxGe8pptwn/xwUolYIDR1JJSYu0WxBP9NO1Mu7o DYWjrQBFcJp4PzDGadUZBTAJAkOpU0xGt5BVTULhPFfQYqglI1xa02E0ARGlFMAeRsZAYJxB+xX0 Am1CnAbMh+qIRo06EqEIlEh/FQQVbZtxFmNCEoCQSQBOJdMSRnw4yFGIwdHmn40oBkBLAGGpIwqK Ew40zo0DnTBcjZlVmJADSf2gTihJvZaQMlRiRORAL562VpZJqgMDaZwEwE1GaWY0JWY0RrmUKcqx cQVF4ywpCUnxdXSmQHpGNSJnvaBIkHi90TmSkANpR1tJp5VJEAmEtPYcFzthNE5yHAFXG3+JWVTQ OL/00ksx/8AU08soW2BSyI+mdRTOZagKVGdiwuAEZgFialbokD/1mpeqBCGhgSq3zKLKKaWUsogl pBjigkElEcaRMrwqe9opBo1aSzHHKKNMMaJssYWmAilzbEaHQndklgFc4MESHnhAQIkcIcCGHHB4 AoonSSGgyyeg6MLLq74cI6scsRVUQkakiCsSqQPRUG21pDCiSimMKGIID3wWJAcbIs3AGXYYeXca LqXcYsotrFQgRkcPGOJHID77kVQBeQxRNA8qqPADDzmokEMqBo0w3DiJBhVKBh5cAAIIIej5RxOe jCK2LEUk1coxvwAzjrrKDKNOOMlIXdCvjG373godhDNOOP7K7A0TONcQ04FBtxSATlQzojbOA6g9 c8stzzxTSr0FEQJD0XlkzmUAJeTg+Qmgn0DC6CTQketpdke3iNMlZMWABFox5EdCVSckN2qYvjdC rMoEA04yyoQTTjbJjPERQeH84NRStQd1r8YjNV/Q7aflHh0gV5EAu1ZcbaUp2lFJj9Mz6tSBVQRY CRQBAw20/4dAD8T/AAUCBbHBBvp6IJAWIBQBwhJlEMgSyKAGKZTBF0xRgxreIAc5CEQXxAqF2AQy K1kdSCDHOAbflKEOQFxJfMpSRpOIAkLo4cQa2TDHQLqRjTkdTh24YAArrHELbAgEWoxAhSoG8rFF POI9y/5QBwS2B4E6wBArDNDKENQxFgY4gAGMU4cLKGABC2hgW+MgAgg88D+BrOILZShDGxw0ilCE Qhe6EAg4PjGJXvRNIMLTW/Aw4jIT2lEdJbwjdLoBDWgMhBvRUIXjyOERQqBiEUFUByogAYlGKCIS AgmEIAJBST0q62CjWIkSAuCJ4wRhIOBwlCVNiIwRjvKUAknGRArgB2IEYBMBgIkoNgKBpIQDC1FE pcZG4QldEEYZAQiVOvrwBYJswFt2JAwymRIOa7yHFRbwlisToJQC8Io56mCFKHWJmnD0hgF8YJEQ XsCEtxXgFcUJAJm2CR2HTEI0nISnOlhgCWqe5hhJGf+IH84pEL6UgkkswpUJfTGd16yrGMgoxji6 EROmVC8AkeknNUuUiRQIxAIBcGYBlimuEgQAAxb45xYe8ASJBIANARBBbzbBmVoMDiMB+EsRZBGA U+xFj95sSG+S4lHRSCIAO8ojg5Iis1cwTSBTmIk6SqGCofwhHXYswAKEAE9CBCAXAVgAPAPQCc60 gjkGYFlBhnARsoYTDEJlDAx6Y4tTPOAPxfFCUjjBgAQogXp9AaYxMMIDJaijFZ8QAUXY2SuGCuQb KhzIik7Dh8YS8id+hWMAFpvMoSHApKMoADCTsgAERCoz4llABuaFwYsogiHPABM3V8vaO+YhEHyY DUhqlNrPcLb2trjNrW53y9ve+va3wC3ID4NL3OIa97jITS5j9JWBThbkCU2QAhkoxRiOKje5L8yL KocwhACQ9gcTCIAE8hCV7k5EICtwATk2cBEoOCSAeRFNAWBCEHiqZykIVEcZLuEgXwAjt/4AUSdw IMGCBg8iPKgsgLp0BQgZTMZwHMNJBQJgrJVQ4AQmogYO6aAhgDUqBdSNK6BkI0t1AYapS7GiYC5O AVh1C4Wyl65WvlqSYeiygIRhVjBOGFigAImTLZ9CjSp1KkFiGDFy68KAIEWBAUIFwBTgFCKhAsfB GgUqmVeMFAS2wHjKpQaBU5xSRRmgV60ALVq1IdjrZDGGBUAEuMhlYzgJDCUioBQuwK1aTjdsVafi Qd7Onj8npHjqVABdQzILBCeUB8ZfDBcSZLVlyxBGAnOpyyU0RoAhDCc4RVDX89UAngpsWSkQmNMC a76eFIVXXYmlBZCcfR0ASwARE5tXEP6YZTro8uajThZYABOx6V3V9QpQYVgADxdOxhKYxzoJr2SC CrRCXQVc4EEBS4ARgBafBWCOOlM00QsCcwmkjFNCJNZXNMcRNAgIH+rkFUoaIaFAANmkJNAfJ6U0 03kvwrhRIAJBAsk4qAmUw0ABREORBBB0M8wMCRnDgATPCMTHEOrQhxEDF5mVl1BTGBDAJgQV49RC lriGkR+VuKgNJIwoUs6O4CxU5Sk8GEBAZgEQUMBI5MVYp50tGeBUlHd6NgwJJfhxEDAMDXoKNU+p IpAxiZwjkCGB6pdDHnqooCOfl2JKECQDbZqpnQGooI6FnpJaqqmn5uUgqquy2qqrrwnCGquss9Jq UEAAOw== ------=_20030310123809_64756--